// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013-2017 ARM Limited, All Rights Reserved.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#include <linux/acpi.h>
#include <linux/acpi_iort.h>
#include <linux/bitfield.h>
#include <linux/bitmap.h>
#include <linux/cpu.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/dma-iommu.h>
#include <linux/efi.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/irqdomain.h>
#include <linux/list.h>
#include <linux/log2.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/syscore_ops.h>

#include <linux/irqchip.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/irqchip/arm-gic-v4.h>

#include <asm/cputype.h>
#include <asm/exception.h>

#include "irq-gic-common.h"

#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
#define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1)
#define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2)

#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1)

#define ITS_COL_TARGET_ADDR_MASK 15

static u32 lpi_id_bits;

/*
 * We allocate memory for PROPBASE to cover 2 ^ lpi_id_bits LPIs to
 * deal with (one configuration byte per interrupt). PENDBASE has to
 * be 64kB aligned (one bit per LPI, plus 8192 bits for SPI/PPI/SGI).
 */
#define LPI_NRBITS lpi_id_bits
#define LPI_PROPBASE_SZ ALIGN(BIT(LPI_NRBITS), SZ_64K)
#define LPI_PENDBASE_SZ ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)

#define LPI_PROP_DEFAULT_PRIO GICD_INT_DEF_PRI

/*
 * Collection structure - just an ID, and a redistributor address to
 * ping. We use one per CPU as a bag of interrupts assigned to this
 * CPU.
 */
struct its_collection {
    u64 target_address;
    u16 col_id;
};

/*
 * The ITS_BASER structure - contains memory information, cached
 * value of BASER register configuration and ITS page size.
 */
struct its_baser {
    void *base;
    u64 val;
    u32 order;
    u32 psz;
};

struct its_device;

/*
 * The ITS structure - contains most of the infrastructure, with the
 * top-level MSI domain, the command queue, the collections, and the
 * list of devices writing to it.
 *
 * dev_alloc_lock has to be taken for device allocations, while the
 * spinlock must be taken to parse data structures such as the device
 * list.
 */
struct its_node {
    raw_spinlock_t lock;
    struct mutex dev_alloc_lock;
    struct list_head entry;
    void __iomem *base;
    void __iomem *sgir_base;
    phys_addr_t phys_base;
    struct its_cmd_block *cmd_base;
    struct its_cmd_block *cmd_write;
    struct its_baser tables[GITS_BASER_NR_REGS];
    struct its_collection *collections;
    struct fwnode_handle *fwnode_handle;
    u64 (*get_msi_base)(struct its_device *its_dev);
    u64 typer;
    u64 cbaser_save;
    u32 ctlr_save;
    u32 mpidr;
    struct list_head its_device_list;
    u64 flags;
    unsigned long list_nr;
    int numa_node;
    unsigned int msi_domain_flags;
    u32 pre_its_base; /* for Socionext Synquacer */
    int vlpi_redist_offset;
};

#define is_v4(its) (!!((its)->typer & GITS_TYPER_VLPIS))
#define is_v4_1(its) (!!((its)->typer & GITS_TYPER_VMAPP))
#define device_ids(its) (FIELD_GET(GITS_TYPER_DEVBITS, (its)->typer) + 1)

#define ITS_ITT_ALIGN SZ_256

/* The maximum number of VPEID bits supported by VLPI commands */
#define ITS_MAX_VPEID_BITS                                                                                             \
    ( {                                                                                                                \
        int nvpeid = 16;                                                                                               \
        if (gic_rdists->has_rvpeid && gic_rdists->gicd_typer2 & GICD_TYPER2_VIL)                                       \
            nvpeid = 1 + (gic_rdists->gicd_typer2 & GICD_TYPER2_VID);                                                  \
                                                                                                                       \
        nvpeid;                                                                                                        \
    })
#define ITS_MAX_VPEID (1 << (ITS_MAX_VPEID_BITS))

/* Convert page order to size in bytes */
#define PAGE_ORDER_TO_SIZE(o) (PAGE_SIZE << (o))

struct event_lpi_map {
    unsigned long *lpi_map;
    u16 *col_map;
    irq_hw_number_t lpi_base;
    int nr_lpis;
    raw_spinlock_t vlpi_lock;
    struct its_vm *vm;
    struct its_vlpi_map *vlpi_maps;
    int nr_vlpis;
};

/*
 * The ITS view of a device - belongs to an ITS, owns an interrupt
 * translation table, and a list of interrupts.  If it some of its
 * LPIs are injected into a guest (GICv4), the event_map.vm field
 * indicates which one.
 */
struct its_device {
    struct list_head entry;
    struct its_node *its;
    struct event_lpi_map event_map;
    void *itt;
    u32 nr_ites;
    u32 device_id;
    bool shared;
};

static struct {
    raw_spinlock_t lock;
    struct its_device *dev;
    struct its_vpe **vpes;
    int next_victim;
} vpe_proxy;

struct cpu_lpi_count {
    atomic_t managed;
    atomic_t unmanaged;
};

static DEFINE_PER_CPU(struct cpu_lpi_count, cpu_lpi_count);

static LIST_HEAD(its_nodes);
static DEFINE_RAW_SPINLOCK(its_lock);
static struct rdists *gic_rdists;
static struct irq_domain *its_parent;

static unsigned long its_list_map;
static u16 vmovp_seq_num;
static DEFINE_RAW_SPINLOCK(vmovp_lock);

static DEFINE_IDA(its_vpeid_ida);

#define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist))
#define gic_data_rdist_cpu(cpu) (per_cpu_ptr(gic_rdists->rdist, cpu))
#define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)
#define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K)

/*
 * Skip ITSs that have no vLPIs mapped, unless we're on GICv4.1, as we
 * always have vSGIs mapped.
 */
static bool require_its_list_vmovp(struct its_vm *vm, struct its_node *its)
{
    return (gic_rdists->has_rvpeid || vm->vlpi_count[its->list_nr]);
}

static u16 get_its_list(struct its_vm *vm)
{
    struct its_node *its;
    unsigned long its_list = 0;

    list_for_each_entry(its, &its_nodes, entry)
    {
        if (!is_v4(its)) {
            continue;
        }

        if (require_its_list_vmovp(vm, its)) {
            __set_bit(its->list_nr, &its_list);
        }
    }

    return (u16)its_list;
}

static inline u32 its_get_event_id(struct irq_data *d)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    return d->hwirq - its_dev->event_map.lpi_base;
}

static struct its_collection *dev_event_to_col(struct its_device *its_dev, u32 event)
{
    struct its_node *its = its_dev->its;

    return its->collections + its_dev->event_map.col_map[event];
}

static struct its_vlpi_map *dev_event_to_vlpi_map(struct its_device *its_dev, u32 event)
{
    if (WARN_ON_ONCE(event >= its_dev->event_map.nr_lpis)) {
        return NULL;
    }

    return &its_dev->event_map.vlpi_maps[event];
}

static struct its_vlpi_map *get_vlpi_map(struct irq_data *d)
{
    if (irqd_is_forwarded_to_vcpu(d)) {
        struct its_device *its_dev = irq_data_get_irq_chip_data(d);
        u32 event = its_get_event_id(d);

        return dev_event_to_vlpi_map(its_dev, event);
    }

    return NULL;
}

static int vpe_to_cpuid_lock(struct its_vpe *vpe, unsigned long *flags)
{
    raw_spin_lock_irqsave(&vpe->vpe_lock, *flags);
    return vpe->col_idx;
}

static void vpe_to_cpuid_unlock(struct its_vpe *vpe, unsigned long flags)
{
    raw_spin_unlock_irqrestore(&vpe->vpe_lock, flags);
}

static int irq_to_cpuid_lock(struct irq_data *d, unsigned long *flags)
{
    struct its_vlpi_map *map = get_vlpi_map(d);
    int cpu;

    if (map) {
        cpu = vpe_to_cpuid_lock(map->vpe, flags);
    } else {
        /* Physical LPIs are already locked via the irq_desc lock */
        struct its_device *its_dev = irq_data_get_irq_chip_data(d);
        cpu = its_dev->event_map.col_map[its_get_event_id(d)];
        /* Keep GCC quiet... */
        *flags = 0;
    }

    return cpu;
}

static void irq_to_cpuid_unlock(struct irq_data *d, unsigned long flags)
{
    struct its_vlpi_map *map = get_vlpi_map(d);

    if (map) {
        vpe_to_cpuid_unlock(map->vpe, flags);
    }
}

static struct its_collection *valid_col(struct its_collection *col)
{
    if (WARN_ON_ONCE(col->target_address & GENMASK_ULL(ITS_COL_TARGET_ADDR_MASK, 0))) {
        return NULL;
    }

    return col;
}

static struct its_vpe *valid_vpe(struct its_node *its, struct its_vpe *vpe)
{
    if (valid_col(its->collections + vpe->col_idx)) {
        return vpe;
    }

    return NULL;
}

/*
 * ITS command descriptors - parameters to be encoded in a command
 * block.
 */
struct its_cmd_desc {
    union {
        struct {
            struct its_device *dev;
            u32 event_id;
        } its_inv_cmd;

        struct {
            struct its_device *dev;
            u32 event_id;
        } its_clear_cmd;

        struct {
            struct its_device *dev;
            u32 event_id;
        } its_int_cmd;

        struct {
            struct its_device *dev;
            int valid;
        } its_mapd_cmd;

        struct {
            struct its_collection *col;
            int valid;
        } its_mapc_cmd;

        struct {
            struct its_device *dev;
            u32 phys_id;
            u32 event_id;
        } its_mapti_cmd;

        struct {
            struct its_device *dev;
            struct its_collection *col;
            u32 event_id;
        } its_movi_cmd;

        struct {
            struct its_device *dev;
            u32 event_id;
        } its_discard_cmd;

        struct {
            struct its_collection *col;
        } its_invall_cmd;

        struct {
            struct its_vpe *vpe;
        } its_vinvall_cmd;

        struct {
            struct its_vpe *vpe;
            struct its_collection *col;
            bool valid;
        } its_vmapp_cmd;

        struct {
            struct its_vpe *vpe;
            struct its_device *dev;
            u32 virt_id;
            u32 event_id;
            bool db_enabled;
        } its_vmapti_cmd;

        struct {
            struct its_vpe *vpe;
            struct its_device *dev;
            u32 event_id;
            bool db_enabled;
        } its_vmovi_cmd;

        struct {
            struct its_vpe *vpe;
            struct its_collection *col;
            u16 seq_num;
            u16 its_list;
        } its_vmovp_cmd;

        struct {
            struct its_vpe *vpe;
        } its_invdb_cmd;

        struct {
            struct its_vpe *vpe;
            u8 sgi;
            u8 priority;
            bool enable;
            bool group;
            bool clear;
        } its_vsgi_cmd;
    };
};

/*
 * The ITS command block, which is what the ITS actually parses.
 */
struct its_cmd_block {
    union {
        u64 raw_cmd[4];
        __le64 raw_cmd_le[4];
    };
};

#define ITS_CMD_QUEUE_SZ SZ_64K
#define ITS_CMD_QUEUE_NR_ENTRIES (ITS_CMD_QUEUE_SZ / sizeof(struct its_cmd_block))

typedef struct its_collection *(*its_cmd_builder_t)(struct its_node *, struct its_cmd_block *, struct its_cmd_desc *);

typedef struct its_vpe *(*its_cmd_vbuilder_t)(struct its_node *, struct its_cmd_block *, struct its_cmd_desc *);

static void its_mask_encode(u64 *raw_cmd, u64 val, int h, int l)
{
    u64 mask = GENMASK_ULL(h, l);
    *raw_cmd &= ~mask;
    *raw_cmd |= (val << l) & mask;
}

static void its_encode_cmd(struct its_cmd_block *cmd, u8 cmd_nr)
{
    its_mask_encode(&cmd->raw_cmd[0], cmd_nr, 0x7, 0);
}

static void its_encode_devid(struct its_cmd_block *cmd, u32 devid)
{
    its_mask_encode(&cmd->raw_cmd[0], devid, 0x3f, 0x20);
}

static void its_encode_event_id(struct its_cmd_block *cmd, u32 id)
{
    its_mask_encode(&cmd->raw_cmd[1], id, 0x1f, 0);
}

static void its_encode_phys_id(struct its_cmd_block *cmd, u32 phys_id)
{
    its_mask_encode(&cmd->raw_cmd[1], phys_id, 0x3f, 0x20);
}

static void its_encode_size(struct its_cmd_block *cmd, u8 size)
{
    its_mask_encode(&cmd->raw_cmd[1], size, 0x4, 0x0);
}

static void its_encode_itt(struct its_cmd_block *cmd, u64 itt_addr)
{
    its_mask_encode(&cmd->raw_cmd[0x2], itt_addr >> 0x8, 0x33, 0x8);
}

static void its_encode_valid(struct its_cmd_block *cmd, int valid)
{
    its_mask_encode(&cmd->raw_cmd[0x2], !!valid, 0x3f, 0x3f);
}

static void its_encode_target(struct its_cmd_block *cmd, u64 target_addr)
{
    its_mask_encode(&cmd->raw_cmd[0x2], target_addr >> 0x10, 0x33, 0x10);
}

static void its_encode_collection(struct its_cmd_block *cmd, u16 col)
{
    its_mask_encode(&cmd->raw_cmd[0x2], col, 0xf, 0);
}

static void its_encode_vpeid(struct its_cmd_block *cmd, u16 vpeid)
{
    its_mask_encode(&cmd->raw_cmd[1], vpeid, 0x2f, 0x20);
}

static void its_encode_virt_id(struct its_cmd_block *cmd, u32 virt_id)
{
    its_mask_encode(&cmd->raw_cmd[0x2], virt_id, 0x1f, 0x0);
}

static void its_encode_db_phys_id(struct its_cmd_block *cmd, u32 db_phys_id)
{
    its_mask_encode(&cmd->raw_cmd[0x2], db_phys_id, 0x3f, 0x20);
}

static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
{
    its_mask_encode(&cmd->raw_cmd[0x2], db_valid, 0, 0);
}

static void its_encode_seq_num(struct its_cmd_block *cmd, u16 seq_num)
{
    its_mask_encode(&cmd->raw_cmd[0], seq_num, 0x2f, 0x20);
}

static void its_encode_its_list(struct its_cmd_block *cmd, u16 its_list)
{
    its_mask_encode(&cmd->raw_cmd[1], its_list, 0xf, 0);
}

static void its_encode_vpt_addr(struct its_cmd_block *cmd, u64 vpt_pa)
{
    its_mask_encode(&cmd->raw_cmd[0x3], vpt_pa >> 0x10, 0x33, 0x10);
}

static void its_encode_vpt_size(struct its_cmd_block *cmd, u8 vpt_size)
{
    its_mask_encode(&cmd->raw_cmd[0x3], vpt_size, 0x4, 0);
}

static void its_encode_vconf_addr(struct its_cmd_block *cmd, u64 vconf_pa)
{
    its_mask_encode(&cmd->raw_cmd[0], vconf_pa >> 0x10, 0x33, 0x10);
}

static void its_encode_alloc(struct its_cmd_block *cmd, bool alloc)
{
    its_mask_encode(&cmd->raw_cmd[0], alloc, 0x8, 0x8);
}

static void its_encode_ptz(struct its_cmd_block *cmd, bool ptz)
{
    its_mask_encode(&cmd->raw_cmd[0], ptz, 0x9, 0x9);
}

static void its_encode_vmapp_default_db(struct its_cmd_block *cmd, u32 vpe_db_lpi)
{
    its_mask_encode(&cmd->raw_cmd[1], vpe_db_lpi, 0x1f, 0);
}

static void its_encode_vmovp_default_db(struct its_cmd_block *cmd, u32 vpe_db_lpi)
{
    its_mask_encode(&cmd->raw_cmd[0x3], vpe_db_lpi, 0x1f, 0);
}

static void its_encode_db(struct its_cmd_block *cmd, bool db)
{
    its_mask_encode(&cmd->raw_cmd[0x2], db, 0x3f, 0x3f);
}

static void its_encode_sgi_intid(struct its_cmd_block *cmd, u8 sgi)
{
    its_mask_encode(&cmd->raw_cmd[0], sgi, 0x23, 0x20);
}

static void its_encode_sgi_priority(struct its_cmd_block *cmd, u8 prio)
{
    its_mask_encode(&cmd->raw_cmd[0], prio >> 0x4, 0x17, 0x14);
}

static void its_encode_sgi_group(struct its_cmd_block *cmd, bool grp)
{
    its_mask_encode(&cmd->raw_cmd[0], grp, 0xa, 0xa);
}

static void its_encode_sgi_clear(struct its_cmd_block *cmd, bool clr)
{
    its_mask_encode(&cmd->raw_cmd[0], clr, 0x9, 0x9);
}

static void its_encode_sgi_enable(struct its_cmd_block *cmd, bool en)
{
    its_mask_encode(&cmd->raw_cmd[0], en, 0x8, 0x8);
}

static inline void its_fixup_cmd(struct its_cmd_block *cmd)
{
    /* Let's fixup BE commands */
    cmd->raw_cmd_le[0x0] = cpu_to_le64(cmd->raw_cmd[0x0]);
    cmd->raw_cmd_le[0x1] = cpu_to_le64(cmd->raw_cmd[0x1]);
    cmd->raw_cmd_le[0x2] = cpu_to_le64(cmd->raw_cmd[0x2]);
    cmd->raw_cmd_le[0x3] = cpu_to_le64(cmd->raw_cmd[0x3]);
}

static struct its_collection *its_build_mapd_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                 struct its_cmd_desc *desc)
{
    unsigned long itt_addr;
    u8 size = ilog2(desc->its_mapd_cmd.dev->nr_ites);

    itt_addr = virt_to_phys(desc->its_mapd_cmd.dev->itt);
    itt_addr = ALIGN(itt_addr, ITS_ITT_ALIGN);

    its_encode_cmd(cmd, GITS_CMD_MAPD);
    its_encode_devid(cmd, desc->its_mapd_cmd.dev->device_id);
    its_encode_size(cmd, size - 1);
    its_encode_itt(cmd, itt_addr);
    its_encode_valid(cmd, desc->its_mapd_cmd.valid);

    its_fixup_cmd(cmd);

    return NULL;
}

static struct its_collection *its_build_mapc_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                 struct its_cmd_desc *desc)
{
    its_encode_cmd(cmd, GITS_CMD_MAPC);
    its_encode_collection(cmd, desc->its_mapc_cmd.col->col_id);
    its_encode_target(cmd, desc->its_mapc_cmd.col->target_address);
    its_encode_valid(cmd, desc->its_mapc_cmd.valid);

    its_fixup_cmd(cmd);

    return desc->its_mapc_cmd.col;
}

static struct its_collection *its_build_mapti_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                  struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_mapti_cmd.dev, desc->its_mapti_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_MAPTI);
    its_encode_devid(cmd, desc->its_mapti_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_mapti_cmd.event_id);
    its_encode_phys_id(cmd, desc->its_mapti_cmd.phys_id);
    its_encode_collection(cmd, col->col_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_movi_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                 struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_movi_cmd.dev, desc->its_movi_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_MOVI);
    its_encode_devid(cmd, desc->its_movi_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_movi_cmd.event_id);
    its_encode_collection(cmd, desc->its_movi_cmd.col->col_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_discard_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                    struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_discard_cmd.dev, desc->its_discard_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_DISCARD);
    its_encode_devid(cmd, desc->its_discard_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_discard_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_inv_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_inv_cmd.dev, desc->its_inv_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_INV);
    its_encode_devid(cmd, desc->its_inv_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_inv_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_int_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_int_cmd.dev, desc->its_int_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_INT);
    its_encode_devid(cmd, desc->its_int_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_int_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_clear_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                  struct its_cmd_desc *desc)
{
    struct its_collection *col;

    col = dev_event_to_col(desc->its_clear_cmd.dev, desc->its_clear_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_CLEAR);
    its_encode_devid(cmd, desc->its_clear_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_clear_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_col(col);
}

static struct its_collection *its_build_invall_cmd(struct its_node *its, struct its_cmd_block *cmd,
                                                   struct its_cmd_desc *desc)
{
    its_encode_cmd(cmd, GITS_CMD_INVALL);
    its_encode_collection(cmd, desc->its_invall_cmd.col->col_id);

    its_fixup_cmd(cmd);

    return desc->its_invall_cmd.col;
}

static struct its_vpe *its_build_vinvall_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    its_encode_cmd(cmd, GITS_CMD_VINVALL);
    its_encode_vpeid(cmd, desc->its_vinvall_cmd.vpe->vpe_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vinvall_cmd.vpe);
}

static struct its_vpe *its_build_vmapp_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    unsigned long vpt_addr, vconf_addr;
    u64 target;
    bool alloc;

    its_encode_cmd(cmd, GITS_CMD_VMAPP);
    its_encode_vpeid(cmd, desc->its_vmapp_cmd.vpe->vpe_id);
    its_encode_valid(cmd, desc->its_vmapp_cmd.valid);

    if (!desc->its_vmapp_cmd.valid) {
        if (is_v4_1(its)) {
            alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count);
            its_encode_alloc(cmd, alloc);
        }

        goto out;
    }

    vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
    target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;

    its_encode_target(cmd, target);
    its_encode_vpt_addr(cmd, vpt_addr);
    its_encode_vpt_size(cmd, LPI_NRBITS - 1);

    if (!is_v4_1(its)) {
        goto out;
    }

    vconf_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->its_vm->vprop_page));

    alloc = !atomic_fetch_inc(&desc->its_vmapp_cmd.vpe->vmapp_count);

    its_encode_alloc(cmd, alloc);

    /* We can only signal PTZ when alloc==1. Why do we have two bits? */
    its_encode_ptz(cmd, alloc);
    its_encode_vconf_addr(cmd, vconf_addr);
    its_encode_vmapp_default_db(cmd, desc->its_vmapp_cmd.vpe->vpe_db_lpi);

out:
    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vmapp_cmd.vpe);
}

static struct its_vpe *its_build_vmapti_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    u32 db;

    if (!is_v4_1(its) && desc->its_vmapti_cmd.db_enabled) {
        db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
    } else {
        db = 0x3FF;
    }

    its_encode_cmd(cmd, GITS_CMD_VMAPTI);
    its_encode_devid(cmd, desc->its_vmapti_cmd.dev->device_id);
    its_encode_vpeid(cmd, desc->its_vmapti_cmd.vpe->vpe_id);
    its_encode_event_id(cmd, desc->its_vmapti_cmd.event_id);
    its_encode_db_phys_id(cmd, db);
    its_encode_virt_id(cmd, desc->its_vmapti_cmd.virt_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vmapti_cmd.vpe);
}

static struct its_vpe *its_build_vmovi_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    u32 db;

    if (!is_v4_1(its) && desc->its_vmovi_cmd.db_enabled) {
        db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
    } else {
        db = 0x3ff;
    }

    its_encode_cmd(cmd, GITS_CMD_VMOVI);
    its_encode_devid(cmd, desc->its_vmovi_cmd.dev->device_id);
    its_encode_vpeid(cmd, desc->its_vmovi_cmd.vpe->vpe_id);
    its_encode_event_id(cmd, desc->its_vmovi_cmd.event_id);
    its_encode_db_phys_id(cmd, db);
    its_encode_db_valid(cmd, true);

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vmovi_cmd.vpe);
}

static struct its_vpe *its_build_vmovp_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    u64 target;

    target = desc->its_vmovp_cmd.col->target_address + its->vlpi_redist_offset;
    its_encode_cmd(cmd, GITS_CMD_VMOVP);
    its_encode_seq_num(cmd, desc->its_vmovp_cmd.seq_num);
    its_encode_its_list(cmd, desc->its_vmovp_cmd.its_list);
    its_encode_vpeid(cmd, desc->its_vmovp_cmd.vpe->vpe_id);
    its_encode_target(cmd, target);

    if (is_v4_1(its)) {
        its_encode_db(cmd, true);
        its_encode_vmovp_default_db(cmd, desc->its_vmovp_cmd.vpe->vpe_db_lpi);
    }

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vmovp_cmd.vpe);
}

static struct its_vpe *its_build_vinv_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    struct its_vlpi_map *map;

    map = dev_event_to_vlpi_map(desc->its_inv_cmd.dev, desc->its_inv_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_INV);
    its_encode_devid(cmd, desc->its_inv_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_inv_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, map->vpe);
}

static struct its_vpe *its_build_vint_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    struct its_vlpi_map *map;

    map = dev_event_to_vlpi_map(desc->its_int_cmd.dev, desc->its_int_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_INT);
    its_encode_devid(cmd, desc->its_int_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_int_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, map->vpe);
}

static struct its_vpe *its_build_vclear_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    struct its_vlpi_map *map;

    map = dev_event_to_vlpi_map(desc->its_clear_cmd.dev, desc->its_clear_cmd.event_id);

    its_encode_cmd(cmd, GITS_CMD_CLEAR);
    its_encode_devid(cmd, desc->its_clear_cmd.dev->device_id);
    its_encode_event_id(cmd, desc->its_clear_cmd.event_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, map->vpe);
}

static struct its_vpe *its_build_invdb_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    if (WARN_ON(!is_v4_1(its))) {
        return NULL;
    }

    its_encode_cmd(cmd, GITS_CMD_INVDB);
    its_encode_vpeid(cmd, desc->its_invdb_cmd.vpe->vpe_id);

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_invdb_cmd.vpe);
}

static struct its_vpe *its_build_vsgi_cmd(struct its_node *its, struct its_cmd_block *cmd, struct its_cmd_desc *desc)
{
    if (WARN_ON(!is_v4_1(its))) {
        return NULL;
    }

    its_encode_cmd(cmd, GITS_CMD_VSGI);
    its_encode_vpeid(cmd, desc->its_vsgi_cmd.vpe->vpe_id);
    its_encode_sgi_intid(cmd, desc->its_vsgi_cmd.sgi);
    its_encode_sgi_priority(cmd, desc->its_vsgi_cmd.priority);
    its_encode_sgi_group(cmd, desc->its_vsgi_cmd.group);
    its_encode_sgi_clear(cmd, desc->its_vsgi_cmd.clear);
    its_encode_sgi_enable(cmd, desc->its_vsgi_cmd.enable);

    its_fixup_cmd(cmd);

    return valid_vpe(its, desc->its_vsgi_cmd.vpe);
}

static u64 its_cmd_ptr_to_offset(struct its_node *its, struct its_cmd_block *ptr)
{
    return (ptr - its->cmd_base) * sizeof(*ptr);
}

static int its_queue_full(struct its_node *its)
{
    int widx;
    int ridx;

    widx = its->cmd_write - its->cmd_base;
    ridx = readl_relaxed(its->base + GITS_CREADR) / sizeof(struct its_cmd_block);
    /* This is incredibly unlikely to happen, unless the ITS locks up. */
    if (((widx + 1) % ITS_CMD_QUEUE_NR_ENTRIES) == ridx) {
        return 1;
    }

    return 0;
}

static struct its_cmd_block *its_allocate_entry(struct its_node *its)
{
    struct its_cmd_block *cmd;
    u32 count = 0xf4240; /* 1s! */

    while (its_queue_full(its)) {
        count--;
        if (!count) {
            pr_err_ratelimited("ITS queue not draining\n");
            return NULL;
        }
        cpu_relax();
        udelay(1);
    }

    cmd = its->cmd_write++;

    /* Handle queue wrapping */
    if (its->cmd_write == (its->cmd_base + ITS_CMD_QUEUE_NR_ENTRIES)) {
        its->cmd_write = its->cmd_base;
    }

    /* Clear command  */
    cmd->raw_cmd[0x0] = 0;
    cmd->raw_cmd[0x1] = 0;
    cmd->raw_cmd[0x2] = 0;
    cmd->raw_cmd[0x3] = 0;

    return cmd;
}

static struct its_cmd_block *its_post_commands(struct its_node *its)
{
    u64 wr = its_cmd_ptr_to_offset(its, its->cmd_write);

    writel_relaxed(wr, its->base + GITS_CWRITER);

    return its->cmd_write;
}

static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd)
{
    /*
     * Make sure the commands written to memory are observable by
     * the ITS.
     */
    if (its->flags & ITS_FLAGS_CMDQ_NEEDS_FLUSHING) {
        gic_flush_dcache_to_poc(cmd, sizeof(*cmd));
    } else {
        dsb(ishst);
    }
}

static int its_wait_for_range_completion(struct its_node *its, u64 prev_idx, struct its_cmd_block *to)
{
    u64 rd_idx, to_idx, linear_idx;
    u32 count = 0xf4240; /* 1s! */

    /* Linearize to_idx if the command set has wrapped around */
    to_idx = its_cmd_ptr_to_offset(its, to);
    if (to_idx < prev_idx) {
        to_idx += ITS_CMD_QUEUE_SZ;
    }

    linear_idx = prev_idx;

    while (1) {
        s64 delta;

        rd_idx = readl_relaxed(its->base + GITS_CREADR);

        /*
         * Compute the read pointer progress, taking the
         * potential wrap-around into account.
         */
        delta = rd_idx - prev_idx;
        if (rd_idx < prev_idx) {
            delta += ITS_CMD_QUEUE_SZ;
        }

        linear_idx += delta;
        if (linear_idx >= to_idx) {
            break;
        }

        count--;
        if (!count) {
            pr_err_ratelimited("ITS queue timeout (%llu %llu)\n", to_idx, linear_idx);
            return -1;
        }
        prev_idx = rd_idx;
        cpu_relax();
        udelay(1);
    }

    return 0;
}

static void its_build_sync_cmd(struct its_node *its, struct its_cmd_block *sync_cmd, struct its_collection *sync_col)
{
    its_encode_cmd(sync_cmd, GITS_CMD_SYNC);
    its_encode_target(sync_cmd, sync_col->target_address);

    its_fixup_cmd(sync_cmd);
}

void its_send_single_command(struct its_node *its, its_cmd_builder_t builder, struct its_cmd_desc *desc)
{
    struct its_cmd_block *cmd, *sync_cmd, *next_cmd;
    struct its_collection *sync_obj;
    unsigned long flags;
    u64 rd_idx;

    raw_spin_lock_irqsave(&its->lock, flags);

    cmd = its_allocate_entry(its);
    if (!cmd) { /* We're soooooo screewed... */
        raw_spin_unlock_irqrestore(&its->lock, flags);
        return;
    }
    sync_obj = builder(its, cmd, desc);
    its_flush_cmd(its, cmd);

    if (sync_obj) {
        sync_cmd = its_allocate_entry(its);
        if (!sync_cmd) {
            goto post;
        }

        its_build_sync_cmd(its, sync_cmd, sync_obj);
        its_flush_cmd(its, sync_cmd);
    }

post:
    rd_idx = readl_relaxed(its->base + GITS_CREADR);
    next_cmd = its_post_commands(its);
    raw_spin_unlock_irqrestore(&its->lock, flags);

    if (its_wait_for_range_completion(its, rd_idx, next_cmd))
        pr_err_ratelimited("ITS cmd %ps failed\n", builder);
}

static void its_build_vsync_cmd(struct its_node *its, struct its_cmd_block *sync_cmd, struct its_vpe *sync_vpe)
{
    its_encode_cmd(sync_cmd, GITS_CMD_VSYNC);
    its_encode_vpeid(sync_cmd, sync_vpe->vpe_id);

    its_fixup_cmd(sync_cmd);
}

void its_send_single_vcommand(struct its_node *its,  its_cmd_vbuilder_t builder, struct its_cmd_desc *desc)
{
    struct its_cmd_block *cmd, *sync_cmd, *next_cmd;
    struct its_vpe *sync_obj;
    unsigned long flags;
    u64 rd_idx;

    raw_spin_lock_irqsave(&its->lock, flags);

    cmd = its_allocate_entry(its);
    if (!cmd) { /* We're soooooo screewed... */
        raw_spin_unlock_irqrestore(&its->lock, flags);
        return;
    }
    sync_obj = builder(its, cmd, desc);
    its_flush_cmd(its, cmd);

    if (sync_obj) {
        sync_cmd = its_allocate_entry(its);
        if (!sync_cmd) {
            goto post;
        }

        its_build_vsync_cmd(its, sync_cmd, sync_obj);
        its_flush_cmd(its, sync_cmd);
    }

post:
    rd_idx = readl_relaxed(its->base + GITS_CREADR);
    next_cmd = its_post_commands(its);
    raw_spin_unlock_irqrestore(&its->lock, flags);

    if (its_wait_for_range_completion(its, rd_idx, next_cmd))
        pr_err_ratelimited("ITS cmd %ps failed\n", builder);
}

static void its_send_int(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    desc.its_int_cmd.dev = dev;
    desc.its_int_cmd.event_id = event_id;

    its_send_single_command(dev->its, its_build_int_cmd, &desc);
}

static void its_send_clear(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    desc.its_clear_cmd.dev = dev;
    desc.its_clear_cmd.event_id = event_id;

    its_send_single_command(dev->its, its_build_clear_cmd, &desc);
}

static void its_send_inv(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    desc.its_inv_cmd.dev = dev;
    desc.its_inv_cmd.event_id = event_id;

    its_send_single_command(dev->its, its_build_inv_cmd, &desc);
}

static void its_send_mapd(struct its_device *dev, int valid)
{
    struct its_cmd_desc desc;

    desc.its_mapd_cmd.dev = dev;
    desc.its_mapd_cmd.valid = !!valid;

    its_send_single_command(dev->its, its_build_mapd_cmd, &desc);
}

static void its_send_mapc(struct its_node *its, struct its_collection *col, int valid)
{
    struct its_cmd_desc desc;

    desc.its_mapc_cmd.col = col;
    desc.its_mapc_cmd.valid = !!valid;

    its_send_single_command(its, its_build_mapc_cmd, &desc);
}

static void its_send_mapti(struct its_device *dev, u32 irq_id, u32 id)
{
    struct its_cmd_desc desc;

    desc.its_mapti_cmd.dev = dev;
    desc.its_mapti_cmd.phys_id = irq_id;
    desc.its_mapti_cmd.event_id = id;

    its_send_single_command(dev->its, its_build_mapti_cmd, &desc);
}

static void its_send_movi(struct its_device *dev, struct its_collection *col, u32 id)
{
    struct its_cmd_desc desc;

    desc.its_movi_cmd.dev = dev;
    desc.its_movi_cmd.col = col;
    desc.its_movi_cmd.event_id = id;

    its_send_single_command(dev->its, its_build_movi_cmd, &desc);
}

static void its_send_discard(struct its_device *dev, u32 id)
{
    struct its_cmd_desc desc;

    desc.its_discard_cmd.dev = dev;
    desc.its_discard_cmd.event_id = id;

    its_send_single_command(dev->its, its_build_discard_cmd, &desc);
}

static void its_send_invall(struct its_node *its, struct its_collection *col)
{
    struct its_cmd_desc desc;

    desc.its_invall_cmd.col = col;

    its_send_single_command(its, its_build_invall_cmd, &desc);
}

static void its_send_vmapti(struct its_device *dev, u32 id)
{
    struct its_vlpi_map *map = dev_event_to_vlpi_map(dev, id);
    struct its_cmd_desc desc;

    desc.its_vmapti_cmd.vpe = map->vpe;
    desc.its_vmapti_cmd.dev = dev;
    desc.its_vmapti_cmd.virt_id = map->vintid;
    desc.its_vmapti_cmd.event_id = id;
    desc.its_vmapti_cmd.db_enabled = map->db_enabled;

    its_send_single_vcommand(dev->its, its_build_vmapti_cmd, &desc);
}

static void its_send_vmovi(struct its_device *dev, u32 id)
{
    struct its_vlpi_map *map = dev_event_to_vlpi_map(dev, id);
    struct its_cmd_desc desc;

    desc.its_vmovi_cmd.vpe = map->vpe;
    desc.its_vmovi_cmd.dev = dev;
    desc.its_vmovi_cmd.event_id = id;
    desc.its_vmovi_cmd.db_enabled = map->db_enabled;

    its_send_single_vcommand(dev->its, its_build_vmovi_cmd, &desc);
}

static void its_send_vmapp(struct its_node *its, struct its_vpe *vpe, bool valid)
{
    struct its_cmd_desc desc;

    desc.its_vmapp_cmd.vpe = vpe;
    desc.its_vmapp_cmd.valid = valid;
    desc.its_vmapp_cmd.col = &its->collections[vpe->col_idx];

    its_send_single_vcommand(its, its_build_vmapp_cmd, &desc);
}

static void its_send_vmovp(struct its_vpe *vpe)
{
    struct its_cmd_desc desc = {};
    struct its_node *its;
    unsigned long flags;
    int col_id = vpe->col_idx;

    desc.its_vmovp_cmd.vpe = vpe;

    if (!its_list_map) {
        its = list_first_entry(&its_nodes, struct its_node, entry);
        desc.its_vmovp_cmd.col = &its->collections[col_id];
        its_send_single_vcommand(its, its_build_vmovp_cmd, &desc);
        return;
    }

    /*
     * Yet another marvel of the architecture. If using the
     * its_list "feature", we need to make sure that all ITSs
     * receive all VMOVP commands in the same order. The only way
     * to guarantee this is to make vmovp a serialization point.
     *
     * Wall <-- Head.
     */
    raw_spin_lock_irqsave(&vmovp_lock, flags);

    desc.its_vmovp_cmd.seq_num = vmovp_seq_num++;
    desc.its_vmovp_cmd.its_list = get_its_list(vpe->its_vm);

    /* Emit VMOVPs */
    list_for_each_entry(its, &its_nodes, entry)
    {
        if (!is_v4(its)) {
            continue;
        }

        if (!require_its_list_vmovp(vpe->its_vm, its)) {
            continue;
        }

        desc.its_vmovp_cmd.col = &its->collections[col_id];
        its_send_single_vcommand(its, its_build_vmovp_cmd, &desc);
    }

    raw_spin_unlock_irqrestore(&vmovp_lock, flags);
}

static void its_send_vinvall(struct its_node *its, struct its_vpe *vpe)
{
    struct its_cmd_desc desc;

    desc.its_vinvall_cmd.vpe = vpe;
    its_send_single_vcommand(its, its_build_vinvall_cmd, &desc);
}

static void its_send_vinv(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    /*
     * There is no real VINV command. This is just a normal INV,
     * with a VSYNC instead of a SYNC.
     */
    desc.its_inv_cmd.dev = dev;
    desc.its_inv_cmd.event_id = event_id;

    its_send_single_vcommand(dev->its, its_build_vinv_cmd, &desc);
}

static void its_send_vint(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    /*
     * There is no real VINT command. This is just a normal INT,
     * with a VSYNC instead of a SYNC.
     */
    desc.its_int_cmd.dev = dev;
    desc.its_int_cmd.event_id = event_id;

    its_send_single_vcommand(dev->its, its_build_vint_cmd, &desc);
}

static void its_send_vclear(struct its_device *dev, u32 event_id)
{
    struct its_cmd_desc desc;

    /*
     * There is no real VCLEAR command. This is just a normal CLEAR,
     * with a VSYNC instead of a SYNC.
     */
    desc.its_clear_cmd.dev = dev;
    desc.its_clear_cmd.event_id = event_id;

    its_send_single_vcommand(dev->its, its_build_vclear_cmd, &desc);
}

static void its_send_invdb(struct its_node *its, struct its_vpe *vpe)
{
    struct its_cmd_desc desc;

    desc.its_invdb_cmd.vpe = vpe;
    its_send_single_vcommand(its, its_build_invdb_cmd, &desc);
}

/*
 * irqchip functions - assumes MSI, mostly.
 */
static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
{
    struct its_vlpi_map *map = get_vlpi_map(d);
    irq_hw_number_t hwirq;
    void *va;
    u8 *cfg;

    if (map) {
        va = page_address(map->vm->vprop_page);
        hwirq = map->vintid;

        /* Remember the updated property */
        map->properties &= ~clr;
        map->properties |= set | LPI_PROP_GROUP1;
    } else {
        va = gic_rdists->prop_table_va;
        hwirq = d->hwirq;
    }

    cfg = va + hwirq - 0x2000;
    *cfg &= ~clr;
    *cfg |= set | LPI_PROP_GROUP1;

    /*
     * Make the above write visible to the redistributors.
     * And yes, we're flushing exactly: One. Single. Byte.
     * Humpf...
     */
    if (gic_rdists->flags & RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING) {
        gic_flush_dcache_to_poc(cfg, sizeof(*cfg));
    } else {
        dsb(ishst);
    }
}

static void wait_for_syncr(void __iomem *rdbase)
{
    while (readl_relaxed(rdbase + GICR_SYNCR) & 1) {
        cpu_relax();
    }
}

static void direct_lpi_inv(struct irq_data *d)
{
    struct its_vlpi_map *map = get_vlpi_map(d);
    void __iomem *rdbase;
    unsigned long flags;
    u64 val;
    int cpu;

    if (map) {
        struct its_device *its_dev = irq_data_get_irq_chip_data(d);

        WARN_ON(!is_v4_1(its_dev->its));

        val = GICR_INVLPIR_V;
        val |= FIELD_PREP(GICR_INVLPIR_VPEID, map->vpe->vpe_id);
        val |= FIELD_PREP(GICR_INVLPIR_INTID, map->vintid);
    } else {
        val = d->hwirq;
    }

    /* Target the redistributor this LPI is currently routed to */
    cpu = irq_to_cpuid_lock(d, &flags);
    raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
    rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
    gic_write_lpir(val, rdbase + GICR_INVLPIR);

    wait_for_syncr(rdbase);
    raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
    irq_to_cpuid_unlock(d, flags);
}

static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);

    lpi_write_config(d, clr, set);
    if (gic_rdists->has_direct_lpi && (is_v4_1(its_dev->its) || !irqd_is_forwarded_to_vcpu(d))) {
        direct_lpi_inv(d);
    } else if (!irqd_is_forwarded_to_vcpu(d)) {
        its_send_inv(its_dev, its_get_event_id(d));
    } else {
        its_send_vinv(its_dev, its_get_event_id(d));
    }
}

static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);
    struct its_vlpi_map *map;
    /*
     * GICv4.1 does away with the per-LPI nonsense, nothing to do
     * here.
     */
    if (is_v4_1(its_dev->its)) {
        return;
    }
    map = dev_event_to_vlpi_map(its_dev, event);
    if (map->db_enabled == enable) {
        return;
    }
    map->db_enabled = enable;
    /*
     * More fun with the architecture:
     *
     * Ideally, we'd issue a VMAPTI to set the doorbell to its LPI
     * value or to 1023, depending on the enable bit. But that
     * would be issueing a mapping for an /existing/ DevID+EventID
     * pair, which is UNPREDICTABLE. Instead, let's issue a VMOVI
     * to the /same/ vPE, using this opportunity to adjust the
     * doorbell. Mouahahahaha. We loves it, Precious.
     */
    its_send_vmovi(its_dev, event);
}

static void its_mask_irq(struct irq_data *d)
{
    if (irqd_is_forwarded_to_vcpu(d)) {
        its_vlpi_set_doorbell(d, false);
    }

    lpi_update_config(d, LPI_PROP_ENABLED, 0);
}

static void its_unmask_irq(struct irq_data *d)
{
    if (irqd_is_forwarded_to_vcpu(d)) {
        its_vlpi_set_doorbell(d, true);
    }

    lpi_update_config(d, 0, LPI_PROP_ENABLED);
}

static __maybe_unused u32 its_read_lpi_count(struct irq_data *d, int cpu)
{
    if (irqd_affinity_is_managed(d)) {
        return atomic_read(&per_cpu_ptr(&cpu_lpi_count, cpu)->managed);
    }

    return atomic_read(&per_cpu_ptr(&cpu_lpi_count, cpu)->unmanaged);
}

static void its_inc_lpi_count(struct irq_data *d, int cpu)
{
    if (irqd_affinity_is_managed(d)) {
        atomic_inc(&per_cpu_ptr(&cpu_lpi_count, cpu)->managed);
    } else {
        atomic_inc(&per_cpu_ptr(&cpu_lpi_count, cpu)->unmanaged);
    }
}

static void its_dec_lpi_count(struct irq_data *d, int cpu)
{
    if (irqd_affinity_is_managed(d)) {
        atomic_dec(&per_cpu_ptr(&cpu_lpi_count, cpu)->managed);
    } else {
        atomic_dec(&per_cpu_ptr(&cpu_lpi_count, cpu)->unmanaged);
    }
}

static unsigned int cpumask_pick_least_loaded(struct irq_data *d, const struct cpumask *cpu_mask)
{
    unsigned int cpu = nr_cpu_ids, tmp;
    int count = S32_MAX;

    for_each_cpu(tmp, cpu_mask)
    {
        int this_count = its_read_lpi_count(d, tmp);
        if (this_count < count) {
            cpu = tmp;
            count = this_count;
        }
    }

    return cpu;
}

/*
 * As suggested by Thomas Gleixner in:
 * https://lore.kernel.org/r/87h80q2aoc.fsf@nanos.tec.linutronix.de
 */
static int its_select_cpu(struct irq_data *d, const struct cpumask *aff_mask)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    cpumask_var_t tmpmask;
    int cpu, node;

    if (!alloc_cpumask_var(&tmpmask, GFP_ATOMIC)) {
        return -ENOMEM;
    }

    node = its_dev->its->numa_node;

    if (!irqd_affinity_is_managed(d)) {
        /* First try the NUMA node */
        if (node != NUMA_NO_NODE) {
            /*
             * Try the intersection of the affinity mask and the
             * node mask (and the online mask, just to be safe).
             */
            cpumask_and(tmpmask, cpumask_of_node(node), aff_mask);
            cpumask_and(tmpmask, tmpmask, cpu_online_mask);

            /*
             * Ideally, we would check if the mask is empty, and
             * try again on the full node here.
             *
             * But it turns out that the way ACPI describes the
             * affinity for ITSs only deals about memory, and
             * not target CPUs, so it cannot describe a single
             * ITS placed next to two NUMA nodes.
             *
             * Instead, just fallback on the online mask. This
             * diverges from Thomas' suggestion above.
             */
            cpu = cpumask_pick_least_loaded(d, tmpmask);
            if (cpu < nr_cpu_ids) {
                goto out;
            }

            /* If we can't cross sockets, give up */
            if ((its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144)) {
                goto out;
            }

            /* If the above failed, expand the search */
        }

        /* Try the intersection of the affinity and online masks */
        cpumask_and(tmpmask, aff_mask, cpu_online_mask);

        /* If that doesn't fly, the online mask is the last resort */
        if (cpumask_empty(tmpmask)) {
            cpumask_copy(tmpmask, cpu_online_mask);
        }

        cpu = cpumask_pick_least_loaded(d, tmpmask);
    } else {
        cpumask_and(tmpmask, irq_data_get_affinity_mask(d), cpu_online_mask);

        /* If we cannot cross sockets, limit the search to that node */
        if ((its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) && node != NUMA_NO_NODE) {
            cpumask_and(tmpmask, tmpmask, cpumask_of_node(node));
        }

        cpu = cpumask_pick_least_loaded(d, tmpmask);
    }
out:
    free_cpumask_var(tmpmask);

    pr_debug("IRQ%d -> %*pbl CPU%d\n", d->irq, cpumask_pr_args(aff_mask), cpu);
    return cpu;
}

static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val, bool force)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    struct its_collection *target_col;
    u32 id = its_get_event_id(d);
    int cpu, prev_cpu;

    /* A forwarded interrupt should use irq_set_vcpu_affinity */
    if (irqd_is_forwarded_to_vcpu(d)) {
        return -EINVAL;
    }

    prev_cpu = its_dev->event_map.col_map[id];
    its_dec_lpi_count(d, prev_cpu);

    if (!force) {
        cpu = its_select_cpu(d, mask_val);
    } else {
        cpu = cpumask_pick_least_loaded(d, mask_val);
    }

    if (cpu < 0 || cpu >= nr_cpu_ids) {
        goto err;
    }

    /* don't set the affinity when the target cpu is same as current one */
    if (cpu != prev_cpu) {
        target_col = &its_dev->its->collections[cpu];
        its_send_movi(its_dev, target_col, id);
        its_dev->event_map.col_map[id] = cpu;
        irq_data_update_effective_affinity(d, cpumask_of(cpu));
    }

    its_inc_lpi_count(d, cpu);

    return IRQ_SET_MASK_OK_DONE;

err:
    its_inc_lpi_count(d, prev_cpu);
    return -EINVAL;
}

static u64 its_irq_get_msi_base(struct its_device *its_dev)
{
    struct its_node *its = its_dev->its;

    return its->phys_base + GITS_TRANSLATER;
}

static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    struct its_node *its;
    u64 addr;

    its = its_dev->its;
    addr = its->get_msi_base(its_dev);

    msg->address_lo = lower_32_bits(addr);
    msg->address_hi = upper_32_bits(addr);
    msg->data = its_get_event_id(d);

    iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg);
}

static int its_irq_set_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool state)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);

    if (which != IRQCHIP_STATE_PENDING) {
        return -EINVAL;
    }

    if (irqd_is_forwarded_to_vcpu(d)) {
        if (state) {
            its_send_vint(its_dev, event);
        } else {
            its_send_vclear(its_dev, event);
        }
    } else {
        if (state) {
            its_send_int(its_dev, event);
        } else {
            its_send_clear(its_dev, event);
        }
    }

    return 0;
}

static int its_irq_retrigger(struct irq_data *d)
{
    return !its_irq_set_irqchip_state(d, IRQCHIP_STATE_PENDING, true);
}

/*
 * Two favourable cases
 *
 * (a) Either we have a GICv4.1, and all vPEs have to be mapped at all times
 *     for vSGI delivery
 *
 * (b) Or the ITSs do not use a list map, meaning that VMOVP is cheap enough
 *     and we're better off mapping all VPEs always
 *
 * If neither (a) nor (b) is true, then we map vPEs on demand.
 *
 */
static bool gic_requires_eager_mapping(void)
{
    if (!its_list_map || gic_rdists->has_rvpeid) {
        return true;
    }

    return false;
}

static void its_map_vm(struct its_node *its, struct its_vm *vm)
{
    unsigned long flags;

    if (gic_requires_eager_mapping()) {
        return;
    }

    raw_spin_lock_irqsave(&vmovp_lock, flags);

    /*
     * If the VM wasn't mapped yet, iterate over the vpes and get
     * them mapped now.
     */
    vm->vlpi_count[its->list_nr]++;

    if (vm->vlpi_count[its->list_nr] == 1) {
        int i;

        for (i = 0; i < vm->nr_vpes; i++) {
            struct its_vpe *vpe = vm->vpes[i];
            struct irq_data *d = irq_get_irq_data(vpe->irq);

            /* Map the VPE to the first possible CPU */
            vpe->col_idx = cpumask_first(cpu_online_mask);
            its_send_vmapp(its, vpe, true);
            its_send_vinvall(its, vpe);
            irq_data_update_effective_affinity(d, cpumask_of(vpe->col_idx));
        }
    }

    raw_spin_unlock_irqrestore(&vmovp_lock, flags);
}

static void its_unmap_vm(struct its_node *its, struct its_vm *vm)
{
    unsigned long flags;

    /* Not using the ITS list? Everything is always mapped. */
    if (gic_requires_eager_mapping()) {
        return;
    }

    raw_spin_lock_irqsave(&vmovp_lock, flags);

    if (!--vm->vlpi_count[its->list_nr]) {
        int i;

        for (i = 0; i < vm->nr_vpes; i++) {
            its_send_vmapp(its, vm->vpes[i], false);
        }
    }

    raw_spin_unlock_irqrestore(&vmovp_lock, flags);
}

static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);
    int ret = 0;

    if (!info->map) {
        return -EINVAL;
    }

    raw_spin_lock(&its_dev->event_map.vlpi_lock);

    if (!its_dev->event_map.vm) {
        struct its_vlpi_map *maps;

        maps = kcalloc(its_dev->event_map.nr_lpis, sizeof(*maps), GFP_ATOMIC);
        if (!maps) {
            ret = -ENOMEM;
            goto out;
        }

        its_dev->event_map.vm = info->map->vm;
        its_dev->event_map.vlpi_maps = maps;
    } else if (its_dev->event_map.vm != info->map->vm) {
        ret = -EINVAL;
        goto out;
    }

    /* Get our private copy of the mapping information */
    its_dev->event_map.vlpi_maps[event] = *info->map;

    if (irqd_is_forwarded_to_vcpu(d)) {
        /* Already mapped, move it around */
        its_send_vmovi(its_dev, event);
    } else {
        /* Ensure all the VPEs are mapped on this ITS */
        its_map_vm(its_dev->its, info->map->vm);

        /*
         * Flag the interrupt as forwarded so that we can
         * start poking the virtual property table.
         */
        irqd_set_forwarded_to_vcpu(d);

        /* Write out the property to the prop table */
        lpi_write_config(d, 0xff, info->map->properties);

        /* Drop the physical mapping */
        its_send_discard(its_dev, event);

        /* and install the virtual one */
        its_send_vmapti(its_dev, event);

        /* Increment the number of VLPIs */
        its_dev->event_map.nr_vlpis++;
    }

out:
    raw_spin_unlock(&its_dev->event_map.vlpi_lock);
    return ret;
}

static int its_vlpi_get(struct irq_data *d, struct its_cmd_info *info)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    struct its_vlpi_map *map;
    int ret = 0;
    raw_spin_lock(&its_dev->event_map.vlpi_lock);
    map = get_vlpi_map(d);
    if (!its_dev->event_map.vm || !map) {
        ret = -EINVAL;
        goto out;
    }
    /* Copy our mapping information to the incoming request */
    *info->map = *map;

out:
    raw_spin_unlock(&its_dev->event_map.vlpi_lock);
    return ret;
}

static int its_vlpi_unmap(struct irq_data *d)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);
    int ret = 0;

    raw_spin_lock(&its_dev->event_map.vlpi_lock);

    if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
        ret = -EINVAL;
        goto out;
    }

    /* Drop the virtual mapping */
    its_send_discard(its_dev, event);

    /* and restore the physical one */
    irqd_clr_forwarded_to_vcpu(d);
    its_send_mapti(its_dev, d->hwirq, event);
    lpi_update_config(d, 0xff, (LPI_PROP_DEFAULT_PRIO | LPI_PROP_ENABLED | LPI_PROP_GROUP1));

    /* Potentially unmap the VM from this ITS */
    its_unmap_vm(its_dev->its, its_dev->event_map.vm);

    /*
     * Drop the refcount and make the device available again if
     * this was the last VLPI.
     */
    if (!--its_dev->event_map.nr_vlpis) {
        its_dev->event_map.vm = NULL;
        kfree(its_dev->event_map.vlpi_maps);
    }

out:
    raw_spin_unlock(&its_dev->event_map.vlpi_lock);
    return ret;
}

static int its_vlpi_prop_update(struct irq_data *d, struct its_cmd_info *info)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);

    if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
        return -EINVAL;
    }

    if (info->cmd_type == PROP_UPDATE_AND_INV_VLPI) {
        lpi_update_config(d, 0xff, info->config);
    } else {
        lpi_write_config(d, 0xff, info->config);
    }
    its_vlpi_set_doorbell(d, !!(info->config & LPI_PROP_ENABLED));

    return 0;
}

static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    struct its_cmd_info *info = vcpu_info;

    /* Need a v4 ITS */
    if (!is_v4(its_dev->its)) {
        return -EINVAL;
    }

    /* Unmap request? */
    if (!info) {
        return its_vlpi_unmap(d);
    }

    switch (info->cmd_type) {
        case MAP_VLPI:
            return its_vlpi_map(d, info);

        case GET_VLPI:
            return its_vlpi_get(d, info);

        case PROP_UPDATE_VLPI:
        case PROP_UPDATE_AND_INV_VLPI:
            return its_vlpi_prop_update(d, info);

        default:
            return -EINVAL;
    }
}

static struct irq_chip its_irq_chip = {
    .name = "ITS",
    .irq_mask = its_mask_irq,
    .irq_unmask = its_unmask_irq,
    .irq_eoi = irq_chip_eoi_parent,
    .irq_set_affinity = its_set_affinity,
    .irq_compose_msi_msg = its_irq_compose_msi_msg,
    .irq_set_irqchip_state = its_irq_set_irqchip_state,
    .irq_retrigger = its_irq_retrigger,
    .irq_set_vcpu_affinity = its_irq_set_vcpu_affinity,
};

/*
 * How we allocate LPIs:
 *
 * lpi_range_list contains ranges of LPIs that are to available to
 * allocate from. To allocate LPIs, just pick the first range that
 * fits the required allocation, and reduce it by the required
 * amount. Once empty, remove the range from the list.
 *
 * To free a range of LPIs, add a free range to the list, sort it and
 * merge the result if the new range happens to be adjacent to an
 * already free block.
 *
 * The consequence of the above is that allocation is cost is low, but
 * freeing is expensive. We assumes that freeing rarely occurs.
 */
#define ITS_MAX_LPI_NRBITS 16 /* 64K LPIs */

static DEFINE_MUTEX(lpi_range_lock);
static LIST_HEAD(lpi_range_list);

struct lpi_range {
    struct list_head entry;
    u32 base_id;
    u32 span;
};

static struct lpi_range *mk_lpi_range(u32 base, u32 span)
{
    struct lpi_range *range;

    range = kmalloc(sizeof(*range), GFP_KERNEL);
    if (range) {
        range->base_id = base;
        range->span = span;
    }

    return range;
}

static int alloc_lpi_range(u32 nr_lpis, u32 *base)
{
    struct lpi_range *range, *tmp;
    int err = -ENOSPC;

    mutex_lock(&lpi_range_lock);

    list_for_each_entry_safe(range, tmp, &lpi_range_list, entry)
    {
        if (range->span >= nr_lpis) {
            *base = range->base_id;
            range->base_id += nr_lpis;
            range->span -= nr_lpis;

            if (range->span == 0) {
                list_del(&range->entry);
                kfree(range);
            }

            err = 0;
            break;
        }
    }

    mutex_unlock(&lpi_range_lock);

    pr_debug("ITS: alloc %u:%u\n", *base, nr_lpis);
    return err;
}

static void merge_lpi_ranges(struct lpi_range *a, struct lpi_range *b)
{
    if (&a->entry == &lpi_range_list || &b->entry == &lpi_range_list) {
        return;
    }
    if (a->base_id + a->span != b->base_id) {
        return;
    }
    b->base_id = a->base_id;
    b->span += a->span;
    list_del(&a->entry);
    kfree(a);
}

static int free_lpi_range(u32 base, u32 nr_lpis)
{
    struct lpi_range *new, *old;

    new = mk_lpi_range(base, nr_lpis);
    if (!new) {
        return -ENOMEM;
    }

    mutex_lock(&lpi_range_lock);

    list_for_each_entry_reverse(old, &lpi_range_list, entry)
    {
        if (old->base_id < base) {
            break;
        }
    }
    /*
     * old is the last element with ->base_id smaller than base,
     * so new goes right after it. If there are no elements with
     * ->base_id smaller than base, &old->entry ends up pointing
     * at the head of the list, and inserting new it the start of
     * the list is the right thing to do in that case as well.
     */
    list_add(&new->entry, &old->entry);
    /*
     * Now check if we can merge with the preceding and/or
     * following ranges.
     */
    merge_lpi_ranges(old, new);
    merge_lpi_ranges(new, list_next_entry(new, entry));

    mutex_unlock(&lpi_range_lock);
    return 0;
}

static int __init its_lpi_init(u32 id_bits)
{
    u32 lpis = (1UL << id_bits) - 0x2000;
    u32 numlpis;
    int err;

    numlpis = 1UL << GICD_TYPER_NUM_LPIS(gic_rdists->gicd_typer);

    if (numlpis > 0x2 && !WARN_ON(numlpis > lpis)) {
        lpis = numlpis;
        pr_info("ITS: Using hypervisor restricted LPI range [%u]\n", lpis);
    }

    /*
     * Initializing the allocator is just the same as freeing the
     * full range of LPIs.
     */
    err = free_lpi_range(0x2000, lpis);
    pr_debug("ITS: Allocator initialized for %u LPIs\n", lpis);
    return err;
}

static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
{
    unsigned long *bitmap = NULL;
    int err = 0;

    do {
        err = alloc_lpi_range(nr_irqs, base);
        if (!err) {
            break;
        }

        nr_irqs /= 0x2;
    } while (nr_irqs > 0);

    if (!nr_irqs) {
        err = -ENOSPC;
    }

    if (err) {
        goto out;
    }

    bitmap = kcalloc(BITS_TO_LONGS(nr_irqs), sizeof(long), GFP_ATOMIC);
    if (!bitmap) {
        goto out;
    }

    *nr_ids = nr_irqs;

out:
    if (!bitmap) {
        *base = *nr_ids = 0;
    }

    return bitmap;
}

static void its_lpi_free(unsigned long *bitmap, u32 base, u32 nr_ids)
{
    WARN_ON(free_lpi_range(base, nr_ids));
    kfree(bitmap);
}

static void gic_reset_prop_table(void *va)
{
    /* Priority 0xa0, Group-1, disabled */
    memset(va, LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1, LPI_PROPBASE_SZ);

    /* Make sure the GIC will observe the written configuration */
    gic_flush_dcache_to_poc(va, LPI_PROPBASE_SZ);
}

static struct page *its_allocate_prop_table(gfp_t gfp_flags)
{
    struct page *prop_page;

    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        gfp_flags |= GFP_DMA32;
    }
    prop_page = alloc_pages(gfp_flags, get_order(LPI_PROPBASE_SZ));
    if (!prop_page) {
        return NULL;
    }

    gic_reset_prop_table(page_address(prop_page));

    return prop_page;
}

static void its_free_prop_table(struct page *prop_page)
{
    free_pages((unsigned long)page_address(prop_page), get_order(LPI_PROPBASE_SZ));
}

static bool gic_check_reserved_range(phys_addr_t addr, unsigned long size)
{
    phys_addr_t start, end, addr_end;
    u64 i;

    /*
     * We don't bother checking for a kdump kernel as by
     * construction, the LPI tables are out of this kernel's
     * memory map.
     */
    if (is_kdump_kernel()) {
        return true;
    }

    addr_end = addr + size - 1;

    for_each_reserved_mem_range(i, &start, &end)
    {
        if (addr >= start && addr_end <= end) {
            return true;
        }
    }

    /* Not found, not a good sign... */
    pr_warn("GICv3: Expected reserved range [%pa:%pa], not found\n", &addr, &addr_end);
    add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
    return false;
}

static int gic_reserve_range(phys_addr_t addr, unsigned long size)
{
    if (efi_enabled(EFI_CONFIG_TABLES)) {
        return efi_mem_reserve_persistent(addr, size);
    }

    return 0;
}

static int __init its_setup_lpi_prop_table(void)
{
    if (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) {
        u64 val;

        val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER);
        lpi_id_bits = (val & GICR_PROPBASER_IDBITS_MASK) + 1;

        gic_rdists->prop_table_pa = val & GENMASK_ULL(0x33, 0xc);
        gic_rdists->prop_table_va = memremap(gic_rdists->prop_table_pa, LPI_PROPBASE_SZ, MEMREMAP_WB);
        gic_reset_prop_table(gic_rdists->prop_table_va);
    } else {
        struct page *page;

        lpi_id_bits = min_t(u32, GICD_TYPER_ID_BITS(gic_rdists->gicd_typer), ITS_MAX_LPI_NRBITS);
        page = its_allocate_prop_table(GFP_NOWAIT);
        if (!page) {
            pr_err("Failed to allocate PROPBASE\n");
            return -ENOMEM;
        }

        gic_rdists->prop_table_pa = page_to_phys(page);
        gic_rdists->prop_table_va = page_address(page);
        WARN_ON(gic_reserve_range(gic_rdists->prop_table_pa, LPI_PROPBASE_SZ));
    }

    pr_info("GICv3: using LPI property table @%pa\n", &gic_rdists->prop_table_pa);

    return its_lpi_init(lpi_id_bits);
}

static const char *its_base_type_string[] = {
    [GITS_BASER_TYPE_DEVICE] = "Devices",         [GITS_BASER_TYPE_VCPU] = "Virtual CPUs",
    [GITS_BASER_TYPE_RESERVED3] = "Reserved (3)", [GITS_BASER_TYPE_COLLECTION] = "Interrupt Collections",
    [GITS_BASER_TYPE_RESERVED5] = "Reserved (5)", [GITS_BASER_TYPE_RESERVED6] = "Reserved (6)",
    [GITS_BASER_TYPE_RESERVED7] = "Reserved (7)",
};

static u64 its_read_baser(struct its_node *its, struct its_baser *baser)
{
    u32 idx = baser - its->tables;

    return gits_read_baser(its->base + GITS_BASER + (idx << 0x3));
}

static void its_write_baser(struct its_node *its, struct its_baser *baser, u64 val)
{
    u32 idx = baser - its->tables;

    gits_write_baser(val, its->base + GITS_BASER + (idx << 0x03));
    baser->val = its_read_baser(its, baser);
}

static int its_setup_baser(struct its_node *its, struct its_baser *baser, u64 cache, u64 shr, u32 order, bool indirect)
{
    u64 val = its_read_baser(its, baser);
    u64 esz = GITS_BASER_ENTRY_SIZE(val);
    u64 type = GITS_BASER_TYPE(val);
    u64 baser_phys, tmp;
    u32 alloc_pages, psz;
    struct page *page;
    void *base;
    gfp_t gfp_flags;

    psz = baser->psz;
    alloc_pages = (PAGE_ORDER_TO_SIZE(order) / psz);
    if (alloc_pages > GITS_BASER_PAGES_MAX) {
        pr_warn("ITS@%pa: %s too large, reduce ITS pages %u->%u\n", &its->phys_base, its_base_type_string[type],
                alloc_pages, GITS_BASER_PAGES_MAX);
        alloc_pages = GITS_BASER_PAGES_MAX;
        order = get_order(GITS_BASER_PAGES_MAX * psz);
    }

    gfp_flags = GFP_KERNEL | __GFP_ZERO;
    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        gfp_flags |= GFP_DMA32;
    }
    page = alloc_pages_node(its->numa_node, gfp_flags, order);
    if (!page) {
        return -ENOMEM;
    }
    base = (void *)page_address(page);
    baser_phys = virt_to_phys(base);
    /* Check if the physical address of the memory is above 48bits */
    if (IS_ENABLED(CONFIG_ARM64_64K_PAGES) && (baser_phys >> 0x30)) {
        /* 52bit PA is supported only when PageSize=64K */
        if (psz != SZ_64K) {
            pr_err("ITS: no 52bit PA support when psz=%d\n", psz);
            free_pages((unsigned long)base, order);
            return -ENXIO;
        }

        /* Convert 52bit PA to 48bit field */
        baser_phys = GITS_BASER_PHYS_52_to_48(baser_phys);
    }
    while (1) {
        val = (baser_phys | (type << GITS_BASER_TYPE_SHIFT) | ((esz - 1) << GITS_BASER_ENTRY_SIZE_SHIFT) |
               ((alloc_pages - 1) << GITS_BASER_PAGES_SHIFT) | cache | shr | GITS_BASER_VALID);

        val |= indirect ? GITS_BASER_INDIRECT : 0x0;

        switch (psz) {
            case SZ_4K:
                val |= GITS_BASER_PAGE_SIZE_4K;
                break;
            case SZ_16K:
                val |= GITS_BASER_PAGE_SIZE_16K;
                break;
            case SZ_64K:
                val |= GITS_BASER_PAGE_SIZE_64K;
                break;
        }

        its_write_baser(its, baser, val);
        tmp = baser->val;

        if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
            if (tmp & GITS_BASER_SHAREABILITY_MASK) {
                tmp &= ~GITS_BASER_SHAREABILITY_MASK;
            } else {
                gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
            }
        }

        if ((val ^ tmp) & GITS_BASER_SHAREABILITY_MASK) {
            /*
             * Shareability didn't stick. Just use
             * whatever the read reported, which is likely
             * to be the only thing this redistributor
             * supports. If that's zero, make it
             * non-cacheable as well.
             */
            shr = tmp & GITS_BASER_SHAREABILITY_MASK;
            if (!shr) {
                cache = GITS_BASER_nC;
                gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
            }
            continue;
        }
        break;
    }

    if (val != tmp) {
        pr_err("ITS@%pa: %s doesn't stick: %llx %llx\n", &its->phys_base, its_base_type_string[type], val, tmp);
        free_pages((unsigned long)base, order);
        return -ENXIO;
    }

    baser->order = order;
    baser->base = base;
    baser->psz = psz;
    tmp = indirect ? GITS_LVL1_ENTRY_SIZE : esz;

    pr_info("ITS@%pa: allocated %d %s @%lx (%s, esz %d, psz %dK, shr %d)\n", &its->phys_base,
            (int)(PAGE_ORDER_TO_SIZE(order) / (int)tmp), its_base_type_string[type], (unsigned long)virt_to_phys(base),
            indirect ? "indirect" : "flat", (int)esz, psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);

    return 0;
}

static bool its_parse_indirect_baser(struct its_node *its, struct its_baser *baser, u32 *order, u32 ids)
{
    u64 tmp = its_read_baser(its, baser);
    u64 type = GITS_BASER_TYPE(tmp);
    u64 esz = GITS_BASER_ENTRY_SIZE(tmp);
    u64 val = GITS_BASER_InnerShareable | GITS_BASER_RaWaWb;
    u32 new_order = *order;
    u32 psz = baser->psz;
    bool indirect = false;

    /* No need to enable Indirection if memory requirement < (psz*2)bytes */
    if ((esz << ids) > (psz * 2)) {
        /*
         * Find out whether hw supports a single or two-level table by
         * table by reading bit at offset '62' after writing '1' to it.
         */
        its_write_baser(its, baser, val | GITS_BASER_INDIRECT);
        indirect = !!(baser->val & GITS_BASER_INDIRECT);

        if (indirect) {
            /*
             * The size of the lvl2 table is equal to ITS page size
             * which is 'psz'. For computing lvl1 table size,
             * subtract ID bits that sparse lvl2 table from 'ids'
             * which is reported by ITS hardware times lvl1 table
             * entry size.
             */
            ids -= ilog2(psz / (int)esz);
            esz = GITS_LVL1_ENTRY_SIZE;
        }
    }

    /*
     * Allocate as many entries as required to fit the
     * range of device IDs that the ITS can grok... The ID
     * space being incredibly sparse, this results in a
     * massive waste of memory if two-level device table
     * feature is not supported by hardware.
     */
    new_order = max_t(u32, get_order(esz << ids), new_order);
    if (new_order >= MAX_ORDER) {
        new_order = MAX_ORDER - 1;
        ids = ilog2(PAGE_ORDER_TO_SIZE(new_order) / (int)esz);
        pr_warn("ITS@%pa: %s Table too large, reduce ids %llu->%u\n", &its->phys_base, its_base_type_string[type],
                device_ids(its), ids);
    }

    *order = new_order;

    return indirect;
}

static u32 compute_common_aff(u64 val)
{
    u32 aff, clpiaff;

    aff = FIELD_GET(GICR_TYPER_AFFINITY, val);
    clpiaff = FIELD_GET(GICR_TYPER_COMMON_LPI_AFF, val);

    return aff & ~(GENMASK(0x1f, 0) >> (clpiaff * 0x8));
}

static u32 compute_its_aff(struct its_node *its)
{
    u64 val;
    u32 svpet;

    /*
     * Reencode the ITS SVPET and MPIDR as a GICR_TYPER, and compute
     * the resulting affinity. We then use that to see if this match
     * our own affinity.
     */
    svpet = FIELD_GET(GITS_TYPER_SVPET, its->typer);
    val = FIELD_PREP(GICR_TYPER_COMMON_LPI_AFF, svpet);
    val |= FIELD_PREP(GICR_TYPER_AFFINITY, its->mpidr);
    return compute_common_aff(val);
}

static struct its_node *find_sibling_its(struct its_node *cur_its)
{
    struct its_node *its;
    u32 aff;

    if (!FIELD_GET(GITS_TYPER_SVPET, cur_its->typer)) {
        return NULL;
    }

    aff = compute_its_aff(cur_its);

    list_for_each_entry(its, &its_nodes, entry)
    {
        u64 baser;

        if (!is_v4_1(its) || its == cur_its) {
            continue;
        }

        if (!FIELD_GET(GITS_TYPER_SVPET, its->typer)) {
            continue;
        }

        if (aff != compute_its_aff(its)) {
            continue;
        }

        /* GICv4.1 guarantees that the vPE table is GITS_BASER2 */
        baser = its->tables[2].val;
        if (!(baser & GITS_BASER_VALID)) {
            continue;
        }

        return its;
    }

    return NULL;
}

static void its_free_tables(struct its_node *its)
{
    int i;

    for (i = 0; i < GITS_BASER_NR_REGS; i++) {
        if (its->tables[i].base) {
            free_pages((unsigned long)its->tables[i].base, its->tables[i].order);
            its->tables[i].base = NULL;
        }
    }
}

static int its_probe_baser_psz(struct its_node *its, struct its_baser *baser)
{
    u64 psz = SZ_64K;

    while (psz) {
        u64 val, gpsz;

        val = its_read_baser(its, baser);
        val &= ~GITS_BASER_PAGE_SIZE_MASK;

        switch (psz) {
            case SZ_64K:
                gpsz = GITS_BASER_PAGE_SIZE_64K;
                break;
            case SZ_16K:
                gpsz = GITS_BASER_PAGE_SIZE_16K;
                break;
            case SZ_4K:
            default:
                gpsz = GITS_BASER_PAGE_SIZE_4K;
                break;
        }

        gpsz >>= GITS_BASER_PAGE_SIZE_SHIFT;

        val |= FIELD_PREP(GITS_BASER_PAGE_SIZE_MASK, gpsz);
        its_write_baser(its, baser, val);

        if (FIELD_GET(GITS_BASER_PAGE_SIZE_MASK, baser->val) == gpsz) {
            break;
        }

        switch (psz) {
            case SZ_64K:
                psz = SZ_16K;
                break;
            case SZ_16K:
                psz = SZ_4K;
                break;
            case SZ_4K:
            default:
                return -1;
        }
    }

    baser->psz = psz;
    return 0;
}

static int its_alloc_tables(struct its_node *its)
{
    u64 shr = GITS_BASER_InnerShareable;
    u64 cache = GITS_BASER_RaWaWb;
    int err, i;

    if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_22375) {
        /* erratum 24313: ignore memory access type */
        cache = GITS_BASER_nCnB;
    }

    for (i = 0; i < GITS_BASER_NR_REGS; i++) {
        struct its_baser *baser = its->tables + i;
        u64 val = its_read_baser(its, baser);
        u64 type = GITS_BASER_TYPE(val);
        bool indirect = false;
        u32 order;

        if (type == GITS_BASER_TYPE_NONE) {
            continue;
        }

        if (its_probe_baser_psz(its, baser)) {
            its_free_tables(its);
            return -ENXIO;
        }

        order = get_order(baser->psz);

        switch (type) {
            case GITS_BASER_TYPE_DEVICE:
                indirect = its_parse_indirect_baser(its, baser, &order, device_ids(its));
                break;

            case GITS_BASER_TYPE_VCPU:
                if (is_v4_1(its)) {
                    struct its_node *sibling;

                    WARN_ON(i != 0x2);
                    if ((sibling = find_sibling_its(its))) {
                        *baser = sibling->tables[0x2];
                        its_write_baser(its, baser, baser->val);
                        continue;
                    }
                }

                indirect = its_parse_indirect_baser(its, baser, &order, ITS_MAX_VPEID_BITS);
                break;
        }

        err = its_setup_baser(its, baser, cache, shr, order, indirect);
        if (err < 0) {
            its_free_tables(its);
            return err;
        }

        /* Update settings which will be used for next BASERn */
        cache = baser->val & GITS_BASER_CACHEABILITY_MASK;
        shr = baser->val & GITS_BASER_SHAREABILITY_MASK;
    }

    return 0;
}

static u64 inherit_vpe_l1_table_from_its(void)
{
    struct its_node *its;
    u64 val;
    u32 aff;

    val = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
    aff = compute_common_aff(val);

    list_for_each_entry(its, &its_nodes, entry)
    {
        u64 baser, addr;

        if (!is_v4_1(its)) {
            continue;
        }

        if (!FIELD_GET(GITS_TYPER_SVPET, its->typer)) {
            continue;
        }

        if (aff != compute_its_aff(its)) {
            continue;
        }

        /* GICv4.1 guarantees that the vPE table is GITS_BASER2 */
        baser = its->tables[2].val;
        if (!(baser & GITS_BASER_VALID)) {
            continue;
        }

        /* We have a winner! */
        gic_data_rdist()->vpe_l1_base = its->tables[0x2].base;

        val = GICR_VPROPBASER_4_1_VALID;
        if (baser & GITS_BASER_INDIRECT) {
            val |= GICR_VPROPBASER_4_1_INDIRECT;
        }
        val |= FIELD_PREP(GICR_VPROPBASER_4_1_PAGE_SIZE, FIELD_GET(GITS_BASER_PAGE_SIZE_MASK, baser));
        switch (FIELD_GET(GITS_BASER_PAGE_SIZE_MASK, baser)) {
            case GIC_PAGE_SIZE_64K:
                addr = GITS_BASER_ADDR_48_to_52(baser);
                break;
            default:
                addr = baser & GENMASK_ULL(0x2f, 0xc);
                break;
        }
        val |= FIELD_PREP(GICR_VPROPBASER_4_1_ADDR, addr >> 0xc);
        val |= FIELD_PREP(GICR_VPROPBASER_SHAREABILITY_MASK, FIELD_GET(GITS_BASER_SHAREABILITY_MASK, baser));
        val |=
            FIELD_PREP(GICR_VPROPBASER_INNER_CACHEABILITY_MASK, FIELD_GET(GITS_BASER_INNER_CACHEABILITY_MASK, baser));
        val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, GITS_BASER_NR_PAGES(baser) - 1);

        return val;
    }

    return 0;
}

static u64 inherit_vpe_l1_table_from_rd(cpumask_t **mask)
{
    u32 aff;
    u64 val;
    int cpu;

    val = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
    aff = compute_common_aff(val);

    for_each_possible_cpu(cpu)
    {
        void __iomem *base = gic_data_rdist_cpu(cpu)->rd_base;

        if (!base || cpu == smp_processor_id()) {
            continue;
        }

        val = gic_read_typer(base + GICR_TYPER);
        if (aff != compute_common_aff(val)) {
            continue;
        }

        /*
         * At this point, we have a victim. This particular CPU
         * has already booted, and has an affinity that matches
         * ours wrt CommonLPIAff. Let's use its own VPROPBASER.
         * Make sure we don't write the Z bit in that case.
         */
        val = gicr_read_vpropbaser(base + SZ_128K + GICR_VPROPBASER);
        val &= ~GICR_VPROPBASER_4_1_Z;

        gic_data_rdist()->vpe_l1_base = gic_data_rdist_cpu(cpu)->vpe_l1_base;
        *mask = gic_data_rdist_cpu(cpu)->vpe_table_mask;

        return val;
    }

    return 0;
}

static bool allocate_vpe_l2_table(int cpu, u32 id)
{
    void __iomem *base = gic_data_rdist_cpu(cpu)->rd_base;
    unsigned int psz, esz, idx, npg, gpsz;
    u64 val;
    struct page *page;
    __le64 *table;

    if (!gic_rdists->has_rvpeid) {
        return true;
    }

    /* Skip non-present CPUs */
    if (!base) {
        return true;
    }

    val = gicr_read_vpropbaser(base + SZ_128K + GICR_VPROPBASER);

    esz = FIELD_GET(GICR_VPROPBASER_4_1_ENTRY_SIZE, val) + 1;
    gpsz = FIELD_GET(GICR_VPROPBASER_4_1_PAGE_SIZE, val);
    npg = FIELD_GET(GICR_VPROPBASER_4_1_SIZE, val) + 1;

    switch (gpsz) {
        default:
            WARN_ON(1);
            fallthrough;
        case GIC_PAGE_SIZE_4K:
            psz = SZ_4K;
            break;
        case GIC_PAGE_SIZE_16K:
            psz = SZ_16K;
            break;
        case GIC_PAGE_SIZE_64K:
            psz = SZ_64K;
            break;
    }

    /* Don't allow vpe_id that exceeds single, flat table limit */
    if (!(val & GICR_VPROPBASER_4_1_INDIRECT)) {
        return (id < (npg * psz / (esz * SZ_8)));
    }

    /* Compute 1st level table index & check if that exceeds table limit */
    idx = id >> ilog2(psz / (esz * SZ_8));
    if (idx >= (npg * psz / GITS_LVL1_ENTRY_SIZE)) {
        return false;
    }
    table = gic_data_rdist_cpu(cpu)->vpe_l1_base;
    /* Allocate memory for 2nd level table */
    if (!table[idx]) {
        page = alloc_pages(GFP_KERNEL | __GFP_ZERO, get_order(psz));
        if (!page) {
            return false;
        }

        /* Flush Lvl2 table to PoC if hw doesn't support coherency */
        if (!(val & GICR_VPROPBASER_SHAREABILITY_MASK)) {
            gic_flush_dcache_to_poc(page_address(page), psz);
        }

        table[idx] = cpu_to_le64(page_to_phys(page) | GITS_BASER_VALID);

        /* Flush Lvl1 entry to PoC if hw doesn't support coherency */
        if (!(val & GICR_VPROPBASER_SHAREABILITY_MASK)) {
            gic_flush_dcache_to_poc(table + idx, GITS_LVL1_ENTRY_SIZE);
        }

        /* Ensure updated table contents are visible to RD hardware */
        dsb(sy);
    }

    return true;
}

static int allocate_vpe_l1_table(void)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val, gpsz, npg, pa;
    unsigned int psz = SZ_64K;
    unsigned int np, epp, esz;
    struct page *page;

    if (!gic_rdists->has_rvpeid) {
        return 0;
    }

    /*
     * if VPENDBASER.Valid is set, disable any previously programmed
     * VPE by setting PendingLast while clearing Valid. This has the
     * effect of making sure no doorbell will be generated and we can
     * then safely clear VPROPBASER.Valid.
     */
    if (gicr_read_vpendbaser(vlpi_base + GICR_VPENDBASER) & GICR_VPENDBASER_Valid) {
        gicr_write_vpendbaser(GICR_VPENDBASER_PendingLast, vlpi_base + GICR_VPENDBASER);
    }

    /*
     * If we can inherit the configuration from another RD, let's do
     * so. Otherwise, we have to go through the allocation process. We
     * assume that all RDs have the exact same requirements, as
     * nothing will work otherwise.
     */
    val = inherit_vpe_l1_table_from_rd(&gic_data_rdist()->vpe_table_mask);
    if (val & GICR_VPROPBASER_4_1_VALID) {
        goto out;
    }

    gic_data_rdist()->vpe_table_mask = kzalloc(sizeof(cpumask_t), GFP_ATOMIC);
    if (!gic_data_rdist()->vpe_table_mask) {
        return -ENOMEM;
    }

    val = inherit_vpe_l1_table_from_its();
    if (val & GICR_VPROPBASER_4_1_VALID) {
        goto out;
    }

    /* First probe the page size */
    val = FIELD_PREP(GICR_VPROPBASER_4_1_PAGE_SIZE, GIC_PAGE_SIZE_64K);
    gicr_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);
    val = gicr_read_vpropbaser(vlpi_base + GICR_VPROPBASER);
    gpsz = FIELD_GET(GICR_VPROPBASER_4_1_PAGE_SIZE, val);
    esz = FIELD_GET(GICR_VPROPBASER_4_1_ENTRY_SIZE, val);

    switch (gpsz) {
        default:
            gpsz = GIC_PAGE_SIZE_4K;
            fallthrough;
        case GIC_PAGE_SIZE_4K:
            psz = SZ_4K;
            break;
        case GIC_PAGE_SIZE_16K:
            psz = SZ_16K;
            break;
        case GIC_PAGE_SIZE_64K:
            psz = SZ_64K;
            break;
    }

    /*
     * Start populating the register from scratch, including RO fields
     * (which we want to print in debug cases...)
     */
    val = 0;
    val |= FIELD_PREP(GICR_VPROPBASER_4_1_PAGE_SIZE, gpsz);
    val |= FIELD_PREP(GICR_VPROPBASER_4_1_ENTRY_SIZE, esz);

    /* How many entries per GIC page? */
    esz++;
    epp = psz / (esz * SZ_8);

    /*
     * If we need more than just a single L1 page, flag the table
     * as indirect and compute the number of required L1 pages.
     */
    if (epp < ITS_MAX_VPEID) {
        int nl2;

        val |= GICR_VPROPBASER_4_1_INDIRECT;

        /* Number of L2 pages required to cover the VPEID space */
        nl2 = DIV_ROUND_UP(ITS_MAX_VPEID, epp);

        /* Number of L1 pages to point to the L2 pages */
        npg = DIV_ROUND_UP(nl2 * SZ_8, psz);
    } else {
        npg = 1;
    }

    val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, npg - 1);

    /* Right, that's the number of CPU pages we need for L1 */
    np = DIV_ROUND_UP(npg * psz, PAGE_SIZE);

    pr_debug("np = %d, npg = %lld, psz = %d, epp = %d, esz = %d\n", np, npg, psz, epp, esz);
    page = alloc_pages(GFP_ATOMIC | __GFP_ZERO, get_order(np * PAGE_SIZE));
    if (!page) {
        return -ENOMEM;
    }

    gic_data_rdist()->vpe_l1_base = page_address(page);
    pa = virt_to_phys(page_address(page));
    WARN_ON(!IS_ALIGNED(pa, psz));

    val |= FIELD_PREP(GICR_VPROPBASER_4_1_ADDR, pa >> 0xc);
    val |= GICR_VPROPBASER_RaWb;
    val |= GICR_VPROPBASER_InnerShareable;
    val |= GICR_VPROPBASER_4_1_Z;
    val |= GICR_VPROPBASER_4_1_VALID;

out:
    gicr_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);
    cpumask_set_cpu(smp_processor_id(), gic_data_rdist()->vpe_table_mask);

    pr_debug("CPU%d: VPROPBASER = %llx %*pbl\n", smp_processor_id(), val,
             cpumask_pr_args(gic_data_rdist()->vpe_table_mask));

    return 0;
}

static int its_alloc_collections(struct its_node *its)
{
    int i;

    its->collections = kcalloc(nr_cpu_ids, sizeof(*its->collections), GFP_KERNEL);
    if (!its->collections) {
        return -ENOMEM;
    }

    for (i = 0; i < nr_cpu_ids; i++) {
        its->collections[i].target_address = ~0ULL;
    }

    return 0;
}

static struct page *its_allocate_pending_table(gfp_t gfp_flags)
{
    struct page *pend_page;

    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        gfp_flags |= GFP_DMA32;
    }
    pend_page = alloc_pages(gfp_flags | __GFP_ZERO, get_order(LPI_PENDBASE_SZ));
    if (!pend_page) {
        return NULL;
    }

    /* Make sure the GIC will observe the zero-ed page */
    gic_flush_dcache_to_poc(page_address(pend_page), LPI_PENDBASE_SZ);

    return pend_page;
}

static void its_free_pending_table(struct page *pt)
{
    free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ));
}

/*
 * Booting with kdump and LPIs enabled is generally fine. Any other
 * case is wrong in the absence of firmware/EFI support.
 */
static bool enabled_lpis_allowed(void)
{
    phys_addr_t addr;
    u64 val;

    /* Check whether the property table is in a reserved region */
    val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER);
    addr = val & GENMASK_ULL(0x33, 0xC);

    return gic_check_reserved_range(addr, LPI_PROPBASE_SZ);
}

static int __init allocate_lpi_tables(void)
{
    u64 val;
    int err, cpu;

    /*
     * If LPIs are enabled while we run this from the boot CPU,
     * flag the RD tables as pre-allocated if the stars do align.
     */
    val = readl_relaxed(gic_data_rdist_rd_base() + GICR_CTLR);
    if ((val & GICR_CTLR_ENABLE_LPIS) && enabled_lpis_allowed()) {
        gic_rdists->flags |= (RDIST_FLAGS_RD_TABLES_PREALLOCATED | RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING);
        pr_info("GICv3: Using preallocated redistributor tables\n");
    }

    err = its_setup_lpi_prop_table();
    if (err) {
        return err;
    }

    /*
     * We allocate all the pending tables anyway, as we may have a
     * mix of RDs that have had LPIs enabled, and some that
     * don't. We'll free the unused ones as each CPU comes online.
     */
    for_each_possible_cpu(cpu)
    {
        struct page *pend_page;

        pend_page = its_allocate_pending_table(GFP_NOWAIT);
        if (!pend_page) {
            pr_err("Failed to allocate PENDBASE for CPU%d\n", cpu);
            return -ENOMEM;
        }

        gic_data_rdist_cpu(cpu)->pend_page = pend_page;
    }

    return 0;
}

static u64 its_clear_vpend_valid(void __iomem *vlpi_base, u64 clr, u64 set)
{
    u32 count = 0xf4240; /* 1s! */
    bool clean;
    u64 val;

    val = gicr_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
    val &= ~GICR_VPENDBASER_Valid;
    val &= ~clr;
    val |= set;
    gicr_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);

    do {
        val = gicr_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
        clean = !(val & GICR_VPENDBASER_Dirty);
        if (!clean) {
            count--;
            cpu_relax();
            udelay(1);
        }
    } while (!clean && count);

    if (unlikely(val & GICR_VPENDBASER_Dirty)) {
        pr_err_ratelimited("ITS virtual pending table not cleaning\n");
        val |= GICR_VPENDBASER_PendingLast;
    }

    return val;
}

static void its_cpu_init_lpis(void)
{
    void __iomem *rbase = gic_data_rdist_rd_base();
    struct page *pend_page;
    phys_addr_t paddr;
    u64 val, tmp;

    if (gic_data_rdist()->lpi_enabled) {
        return;
    }

    val = readl_relaxed(rbase + GICR_CTLR);
    if ((gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) && (val & GICR_CTLR_ENABLE_LPIS)) {
        /*
         * Check that we get the same property table on all
         * RDs. If we don't, this is hopeless.
         */
        paddr = gicr_read_propbaser(rbase + GICR_PROPBASER);
        paddr &= GENMASK_ULL(0x33, 0xC);
        if (WARN_ON(gic_rdists->prop_table_pa != paddr)) {
            add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
        }

        paddr = gicr_read_pendbaser(rbase + GICR_PENDBASER);
        paddr &= GENMASK_ULL(0x33, 0x10);

        WARN_ON(!gic_check_reserved_range(paddr, LPI_PENDBASE_SZ));
        its_free_pending_table(gic_data_rdist()->pend_page);
        gic_data_rdist()->pend_page = NULL;

        goto out;
    }

    pend_page = gic_data_rdist()->pend_page;
    paddr = page_to_phys(pend_page);
    WARN_ON(gic_reserve_range(paddr, LPI_PENDBASE_SZ));

    /* set PROPBASE */
    val = (gic_rdists->prop_table_pa | GICR_PROPBASER_InnerShareable | GICR_PROPBASER_RaWaWb |
           ((LPI_NRBITS - 1) & GICR_PROPBASER_IDBITS_MASK));

    gicr_write_propbaser(val, rbase + GICR_PROPBASER);
    tmp = gicr_read_propbaser(rbase + GICR_PROPBASER);

    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        tmp &= ~GICR_PROPBASER_SHAREABILITY_MASK;
    }

    if ((tmp ^ val) & GICR_PROPBASER_SHAREABILITY_MASK) {
        if (!(tmp & GICR_PROPBASER_SHAREABILITY_MASK)) {
            /*
             * The HW reports non-shareable, we must
             * remove the cacheability attributes as
             * well.
             */
            val &= ~(GICR_PROPBASER_SHAREABILITY_MASK | GICR_PROPBASER_CACHEABILITY_MASK);
            val |= GICR_PROPBASER_nC;
            gicr_write_propbaser(val, rbase + GICR_PROPBASER);
        }
        pr_info_once("GIC: using cache flushing for LPI property table\n");
        gic_rdists->flags |= RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING;
    }

    /* set PENDBASE */
    val = (page_to_phys(pend_page) | GICR_PENDBASER_InnerShareable | GICR_PENDBASER_RaWaWb);

    gicr_write_pendbaser(val, rbase + GICR_PENDBASER);
    tmp = gicr_read_pendbaser(rbase + GICR_PENDBASER);

    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        tmp &= ~GICR_PENDBASER_SHAREABILITY_MASK;
    }

    if (!(tmp & GICR_PENDBASER_SHAREABILITY_MASK)) {
        /*
         * The HW reports non-shareable, we must remove the
         * cacheability attributes as well.
         */
        val &= ~(GICR_PENDBASER_SHAREABILITY_MASK | GICR_PENDBASER_CACHEABILITY_MASK);
        val |= GICR_PENDBASER_nC;
        gicr_write_pendbaser(val, rbase + GICR_PENDBASER);
    }

    /* Enable LPIs */
    val = readl_relaxed(rbase + GICR_CTLR);
    val |= GICR_CTLR_ENABLE_LPIS;
    writel_relaxed(val, rbase + GICR_CTLR);

    if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) {
        void __iomem *vlpi_base = gic_data_rdist_vlpi_base();

        /*
         * It's possible for CPU to receive VLPIs before it is
         * sheduled as a vPE, especially for the first CPU, and the
         * VLPI with INTID larger than 2^(IDbits+1) will be considered
         * as out of range and dropped by GIC.
         * So we initialize IDbits to known value to avoid VLPI drop.
         */
        val = (LPI_NRBITS - 1) & GICR_VPROPBASER_IDBITS_MASK;
        pr_debug("GICv4: CPU%d: Init IDbits to 0x%llx for GICR_VPROPBASER\n", smp_processor_id(), val);
        gicr_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);

        /*
         * Also clear Valid bit of GICR_VPENDBASER, in case some
         * ancient programming gets left in and has possibility of
         * corrupting memory.
         */
        val = its_clear_vpend_valid(vlpi_base, 0, 0);
    }

    if (allocate_vpe_l1_table()) {
        /*
         * If the allocation has failed, we're in massive trouble.
         * Disable direct injection, and pray that no VM was
         * already running...
         */
        gic_rdists->has_rvpeid = false;
        gic_rdists->has_vlpis = false;
    }

    /* Make sure the GIC has seen the above */
    dsb(sy);
out:
    gic_data_rdist()->lpi_enabled = true;
    pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", smp_processor_id(),
            gic_data_rdist()->pend_page ? "allocated" : "reserved", &paddr);
}

static void its_cpu_init_collection(struct its_node *its)
{
    int cpu = smp_processor_id();
    u64 target;

    /* avoid cross node collections and its mapping */
    if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
        struct device_node *cpu_node;

        cpu_node = of_get_cpu_node(cpu, NULL);
        if (its->numa_node != NUMA_NO_NODE && its->numa_node != of_node_to_nid(cpu_node)) {
            return;
        }
    }

    /*
     * We now have to bind each collection to its target
     * redistributor.
     */
    if (gic_read_typer(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
        /*
         * This ITS wants the physical address of the
         * redistributor.
         */
        target = gic_data_rdist()->phys_base;
    } else {
        /* This ITS wants a linear CPU number. */
        target = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
        target = GICR_TYPER_CPU_NUMBER(target) << 0x10;
    }

    /* Perform collection mapping */
    its->collections[cpu].target_address = target;
    its->collections[cpu].col_id = cpu;

    its_send_mapc(its, &its->collections[cpu], 1);
    its_send_invall(its, &its->collections[cpu]);
}

static void its_cpu_init_collections(void)
{
    struct its_node *its;

    raw_spin_lock(&its_lock);

    list_for_each_entry(its, &its_nodes, entry) its_cpu_init_collection(its);

    raw_spin_unlock(&its_lock);
}

static struct its_device *its_find_device(struct its_node *its, u32 dev_id)
{
    struct its_device *its_dev = NULL, *tmp;
    unsigned long flags;

    raw_spin_lock_irqsave(&its->lock, flags);

    list_for_each_entry(tmp, &its->its_device_list, entry)
    {
        if (tmp->device_id == dev_id) {
            its_dev = tmp;
            break;
        }
    }

    raw_spin_unlock_irqrestore(&its->lock, flags);

    return its_dev;
}

static struct its_baser *its_get_baser(struct its_node *its, u32 type)
{
    int i;

    for (i = 0; i < GITS_BASER_NR_REGS; i++) {
        if (GITS_BASER_TYPE(its->tables[i].val) == type) {
            return &its->tables[i];
        }
    }

    return NULL;
}

static bool its_alloc_table_entry(struct its_node *its, struct its_baser *baser, u32 id)
{
    struct page *page;
    u32 esz, idx;
    __le64 *table;

    /* Don't allow device id that exceeds single, flat table limit */
    esz = GITS_BASER_ENTRY_SIZE(baser->val);
    if (!(baser->val & GITS_BASER_INDIRECT)) {
        return (id < (PAGE_ORDER_TO_SIZE(baser->order) / esz));
    }

    /* Compute 1st level table index & check if that exceeds table limit */
    idx = id >> ilog2(baser->psz / esz);
    if (idx >= (PAGE_ORDER_TO_SIZE(baser->order) / GITS_LVL1_ENTRY_SIZE)) {
        return false;
    }

    table = baser->base;

    /* Allocate memory for 2nd level table */
    if (!table[idx]) {
        gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO;

        if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
            gfp_flags |= GFP_DMA32;
        }
        page = alloc_pages_node(its->numa_node, gfp_flags, get_order(baser->psz));
        if (!page) {
            return false;
        }

        /* Flush Lvl2 table to PoC if hw doesn't support coherency */
        if (!(baser->val & GITS_BASER_SHAREABILITY_MASK)) {
            gic_flush_dcache_to_poc(page_address(page), baser->psz);
        }

        table[idx] = cpu_to_le64(page_to_phys(page) | GITS_BASER_VALID);

        /* Flush Lvl1 entry to PoC if hw doesn't support coherency */
        if (!(baser->val & GITS_BASER_SHAREABILITY_MASK)) {
            gic_flush_dcache_to_poc(table + idx, GITS_LVL1_ENTRY_SIZE);
        }

        /* Ensure updated table contents are visible to ITS hardware */
        dsb(sy);
    }

    return true;
}

static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
{
    struct its_baser *baser;
    baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
    /* Don't allow device id that exceeds ITS hardware limit */
    if (!baser) {
        return (ilog2(dev_id) < device_ids(its));
    }
    return its_alloc_table_entry(its, baser, dev_id);
}

static bool its_alloc_vpe_table(u32 vpe_id)
{
    struct its_node *its;
    int cpu;

    /*
     * Make sure the L2 tables are allocated on *all* v4 ITSs. We
     * could try and only do it on ITSs corresponding to devices
     * that have interrupts targeted at this VPE, but the
     * complexity becomes crazy (and you have tons of memory
     * anyway, right?).
     */
    list_for_each_entry(its, &its_nodes, entry)
    {
        struct its_baser *baser;

        if (!is_v4(its)) {
            continue;
        }

        baser = its_get_baser(its, GITS_BASER_TYPE_VCPU);
        if (!baser) {
            return false;
        }

        if (!its_alloc_table_entry(its, baser, vpe_id)) {
            return false;
        }
    }

    /* Non v4.1? No need to iterate RDs and go back early. */
    if (!gic_rdists->has_rvpeid) {
        return true;
    }

    /*
     * Make sure the L2 tables are allocated for all copies of
     * the L1 table on *all* v4.1 RDs.
     */
    for_each_possible_cpu(cpu)
    {
        if (!allocate_vpe_l2_table(cpu, vpe_id)) {
            return false;
        }
    }

    return true;
}

static struct its_device *its_create_device(struct its_node *its, u32 dev_id, int nvecs, bool alloc_lpis)
{
    struct its_device *dev;
    unsigned long *lpi_map = NULL;
    unsigned long flags;
    u16 *col_map = NULL;
    void *itt;
    int lpi_base;
    int nr_lpis;
    int nr_ites;
    int sz;
    gfp_t gfp_flags;

    if (!its_alloc_device_table(its, dev_id)) {
        return NULL;
    }

    if (WARN_ON(!is_power_of_2(nvecs))) {
        nvecs = roundup_pow_of_two(nvecs);
    }

    dev = kzalloc(sizeof(*dev), GFP_KERNEL);
    /*
     * Even if the device wants a single LPI, the ITT must be
     * sized as a power of two (and you need at least one bit...).
     */
    nr_ites = max(0x2, nvecs);
    sz = nr_ites * (FIELD_GET(GITS_TYPER_ITT_ENTRY_SIZE, its->typer) + 1);
    sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
    gfp_flags = GFP_KERNEL;
    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        gfp_flags |= GFP_DMA32;
    }
    itt = kzalloc_node(sz, gfp_flags, its->numa_node);
    if (alloc_lpis) {
        lpi_map = its_lpi_alloc(nvecs, &lpi_base, &nr_lpis);
        if (lpi_map) {
            col_map = kcalloc(nr_lpis, sizeof(*col_map), GFP_KERNEL);
        }
    } else {
        col_map = kcalloc(nr_ites, sizeof(*col_map), GFP_KERNEL);
        nr_lpis = 0;
        lpi_base = 0;
    }

    if (!dev || !itt || !col_map || (!lpi_map && alloc_lpis)) {
        kfree(dev);
        kfree(itt);
        kfree(lpi_map);
        kfree(col_map);
        return NULL;
    }

    gic_flush_dcache_to_poc(itt, sz);

    dev->its = its;
    dev->itt = itt;
    dev->nr_ites = nr_ites;
    dev->event_map.lpi_map = lpi_map;
    dev->event_map.col_map = col_map;
    dev->event_map.lpi_base = lpi_base;
    dev->event_map.nr_lpis = nr_lpis;
    raw_spin_lock_init(&dev->event_map.vlpi_lock);
    dev->device_id = dev_id;
    INIT_LIST_HEAD(&dev->entry);

    raw_spin_lock_irqsave(&its->lock, flags);
    list_add(&dev->entry, &its->its_device_list);
    raw_spin_unlock_irqrestore(&its->lock, flags);

    /* Map device to its ITT */
    its_send_mapd(dev, 1);

    return dev;
}

static void its_free_device(struct its_device *its_dev)
{
    unsigned long flags;

    raw_spin_lock_irqsave(&its_dev->its->lock, flags);
    list_del(&its_dev->entry);
    raw_spin_unlock_irqrestore(&its_dev->its->lock, flags);
    kfree(its_dev->event_map.col_map);
    kfree(its_dev->itt);
    kfree(its_dev);
}

static int its_alloc_device_irq(struct its_device *dev, int nvecs, irq_hw_number_t *hwirq)
{
    int idx;

    /* Find a free LPI region in lpi_map and allocate them. */
    idx = bitmap_find_free_region(dev->event_map.lpi_map, dev->event_map.nr_lpis, get_count_order(nvecs));
    if (idx < 0) {
        return -ENOSPC;
    }

    *hwirq = dev->event_map.lpi_base + idx;

    return 0;
}

static int its_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec, msi_alloc_info_t *info)
{
    struct its_node *its;
    struct its_device *its_dev;
    struct msi_domain_info *msi_info;
    u32 dev_id;
    int err = 0;

    /*
     * We ignore "dev" entirely, and rely on the dev_id that has
     * been passed via the scratchpad. This limits this domain's
     * usefulness to upper layers that definitely know that they
     * are built on top of the ITS.
     */
    dev_id = info->scratchpad[0].ul;

    msi_info = msi_get_domain_info(domain);
    its = msi_info->data;

    if (!gic_rdists->has_direct_lpi && vpe_proxy.dev && vpe_proxy.dev->its == its &&
        dev_id == vpe_proxy.dev->device_id) {
        /* Bad luck. Get yourself a better implementation */
        WARN_ONCE(1, "DevId %x clashes with GICv4 VPE proxy device\n", dev_id);
        return -EINVAL;
    }

    mutex_lock(&its->dev_alloc_lock);
    its_dev = its_find_device(its, dev_id);
    if (its_dev) {
        /*
         * We already have seen this ID, probably through
         * another alias (PCI bridge of some sort). No need to
         * create the device.
         */
        its_dev->shared = true;
        pr_debug("Reusing ITT for devID %x\n", dev_id);
        goto out;
    }

    its_dev = its_create_device(its, dev_id, nvec, true);
    if (!its_dev) {
        err = -ENOMEM;
        goto out;
    }

    pr_debug("ITT %d entries, %d bits\n", nvec, ilog2(nvec));
out:
    mutex_unlock(&its->dev_alloc_lock);
    info->scratchpad[0].ptr = its_dev;
    return err;
}

static struct msi_domain_ops its_msi_domain_ops = {
    .msi_prepare = its_msi_prepare,
};

static int its_irq_gic_domain_alloc(struct irq_domain *domain, unsigned int virq, irq_hw_number_t hwirq)
{
    struct irq_fwspec fwspec;

    if (irq_domain_get_of_node(domain->parent)) {
        fwspec.fwnode = domain->parent->fwnode;
        fwspec.param_count = 0x3;
        fwspec.param[0] = GIC_IRQ_TYPE_LPI;
        fwspec.param[1] = hwirq;
        fwspec.param[0x2] = IRQ_TYPE_EDGE_RISING;
    } else if (is_fwnode_irqchip(domain->parent->fwnode)) {
        fwspec.fwnode = domain->parent->fwnode;
        fwspec.param_count = 0x2;
        fwspec.param[0] = hwirq;
        fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
    } else {
        return -EINVAL;
    }

    return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
}

static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args)
{
    msi_alloc_info_t *info = args;
    struct its_device *its_dev = info->scratchpad[0].ptr;
    struct its_node *its = its_dev->its;
    struct irq_data *irqd;
    irq_hw_number_t hwirq;
    int err;
    int i;

    err = its_alloc_device_irq(its_dev, nr_irqs, &hwirq);
    if (err) {
        return err;
    }

    err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev));
    if (err) {
        return err;
    }

    for (i = 0; i < nr_irqs; i++) {
        err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
        if (err) {
            return err;
        }

        irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, &its_irq_chip, its_dev);
        irqd = irq_get_irq_data(virq + i);
        irqd_set_single_target(irqd);
        irqd_set_affinity_on_activate(irqd);
        pr_debug("ID:%d pID:%d vID:%d\n", (int)(hwirq + i - its_dev->event_map.lpi_base), (int)(hwirq + i), virq + i);
    }

    return 0;
}

static int its_irq_domain_activate(struct irq_domain *domain, struct irq_data *d, bool reserve)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);
    int cpu;

    cpu = its_select_cpu(d, cpu_online_mask);
    if (cpu < 0 || cpu >= nr_cpu_ids) {
        return -EINVAL;
    }

    its_inc_lpi_count(d, cpu);
    its_dev->event_map.col_map[event] = cpu;
    irq_data_update_effective_affinity(d, cpumask_of(cpu));

    /* Map the GIC IRQ and event to the device */
    its_send_mapti(its_dev, d->hwirq, event);
    return 0;
}

static void its_irq_domain_deactivate(struct irq_domain *domain, struct irq_data *d)
{
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    u32 event = its_get_event_id(d);

    its_dec_lpi_count(d, its_dev->event_map.col_map[event]);
    /* Stop the delivery of interrupts */
    its_send_discard(its_dev, event);
}

static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs)
{
    struct irq_data *d = irq_domain_get_irq_data(domain, virq);
    struct its_device *its_dev = irq_data_get_irq_chip_data(d);
    struct its_node *its = its_dev->its;
    int i;

    bitmap_release_region(its_dev->event_map.lpi_map, its_get_event_id(irq_domain_get_irq_data(domain, virq)),
                          get_count_order(nr_irqs));

    for (i = 0; i < nr_irqs; i++) {
        struct irq_data *data = irq_domain_get_irq_data(domain, virq + i);
        /* Nuke the entry in the domain */
        irq_domain_reset_irq_data(data);
    }

    mutex_lock(&its->dev_alloc_lock);

    /*
     * If all interrupts have been freed, start mopping the
     * floor. This is conditionned on the device not being shared.
     */
    if (!its_dev->shared && bitmap_empty(its_dev->event_map.lpi_map, its_dev->event_map.nr_lpis)) {
        its_lpi_free(its_dev->event_map.lpi_map, its_dev->event_map.lpi_base, its_dev->event_map.nr_lpis);

        /* Unmap device/itt */
        its_send_mapd(its_dev, 0);
        its_free_device(its_dev);
    }

    mutex_unlock(&its->dev_alloc_lock);

    irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}

static const struct irq_domain_ops its_domain_ops = {
    .alloc = its_irq_domain_alloc,
    .free = its_irq_domain_free,
    .activate = its_irq_domain_activate,
    .deactivate = its_irq_domain_deactivate,
};

/*
 * This is insane.
 *
 * If a GICv4.0 doesn't implement Direct LPIs (which is extremely
 * likely), the only way to perform an invalidate is to use a fake
 * device to issue an INV command, implying that the LPI has first
 * been mapped to some event on that device. Since this is not exactly
 * cheap, we try to keep that mapping around as long as possible, and
 * only issue an UNMAP if we're short on available slots.
 *
 * Broken by design(tm).
 *
 * GICv4.1, on the other hand, mandates that we're able to invalidate
 * by writing to a MMIO register. It doesn't implement the whole of
 * DirectLPI, but that's good enough. And most of the time, we don't
 * even have to invalidate anything, as the redistributor can be told
 * whether to generate a doorbell or not (we thus leave it enabled,
 * always).
 */
static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe)
{
    /* GICv4.1 doesn't use a proxy, so nothing to do here */
    if (gic_rdists->has_rvpeid) {
        return;
    }

    /* Already unmapped? */
    if (vpe->vpe_proxy_event == -1) {
        return;
    }

    its_send_discard(vpe_proxy.dev, vpe->vpe_proxy_event);
    vpe_proxy.vpes[vpe->vpe_proxy_event] = NULL;

    /*
     * We don't track empty slots at all, so let's move the
     * next_victim pointer if we can quickly reuse that slot
     * instead of nuking an existing entry. Not clear that this is
     * always a win though, and this might just generate a ripple
     * effect... Let's just hope VPEs don't migrate too often.
     */
    if (vpe_proxy.vpes[vpe_proxy.next_victim]) {
        vpe_proxy.next_victim = vpe->vpe_proxy_event;
    }

    vpe->vpe_proxy_event = -1;
}

static void its_vpe_db_proxy_unmap(struct its_vpe *vpe)
{
    /* GICv4.1 doesn't use a proxy, so nothing to do here */
    if (gic_rdists->has_rvpeid) {
        return;
    }

    if (!gic_rdists->has_direct_lpi) {
        unsigned long flags;

        raw_spin_lock_irqsave(&vpe_proxy.lock, flags);
        its_vpe_db_proxy_unmap_locked(vpe);
        raw_spin_unlock_irqrestore(&vpe_proxy.lock, flags);
    }
}

static void its_vpe_db_proxy_map_locked(struct its_vpe *vpe)
{
    /* GICv4.1 doesn't use a proxy, so nothing to do here */
    if (gic_rdists->has_rvpeid) {
        return;
    }

    /* Already mapped? */
    if (vpe->vpe_proxy_event != -1) {
        return;
    }

    /* This slot was already allocated. Kick the other VPE out. */
    if (vpe_proxy.vpes[vpe_proxy.next_victim]) {
        its_vpe_db_proxy_unmap_locked(vpe_proxy.vpes[vpe_proxy.next_victim]);
    }

    /* Map the new VPE instead */
    vpe_proxy.vpes[vpe_proxy.next_victim] = vpe;
    vpe->vpe_proxy_event = vpe_proxy.next_victim;
    vpe_proxy.next_victim = (vpe_proxy.next_victim + 1) % vpe_proxy.dev->nr_ites;

    vpe_proxy.dev->event_map.col_map[vpe->vpe_proxy_event] = vpe->col_idx;
    its_send_mapti(vpe_proxy.dev, vpe->vpe_db_lpi, vpe->vpe_proxy_event);
}

static void its_vpe_db_proxy_move(struct its_vpe *vpe, int from, int to)
{
    unsigned long flags;
    struct its_collection *target_col;

    /* GICv4.1 doesn't use a proxy, so nothing to do here */
    if (gic_rdists->has_rvpeid) {
        return;
    }

    if (gic_rdists->has_direct_lpi) {
        void __iomem *rdbase;

        rdbase = per_cpu_ptr(gic_rdists->rdist, from)->rd_base;
        gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_CLRLPIR);
        wait_for_syncr(rdbase);

        return;
    }

    raw_spin_lock_irqsave(&vpe_proxy.lock, flags);

    its_vpe_db_proxy_map_locked(vpe);

    target_col = &vpe_proxy.dev->its->collections[to];
    its_send_movi(vpe_proxy.dev, target_col, vpe->vpe_proxy_event);
    vpe_proxy.dev->event_map.col_map[vpe->vpe_proxy_event] = to;

    raw_spin_unlock_irqrestore(&vpe_proxy.lock, flags);
}

static int its_vpe_set_affinity(struct irq_data *d, const struct cpumask *mask_val, bool force)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    int from, cpu = cpumask_first(mask_val);
    unsigned long flags;

    /*
     * Changing affinity is mega expensive, so let's be as lazy as
     * we can and only do it if we really have to. Also, if mapped
     * into the proxy device, we need to move the doorbell
     * interrupt to its new location.
     *
     * Another thing is that changing the affinity of a vPE affects
     * *other interrupts* such as all the vLPIs that are routed to
     * this vPE. This means that the irq_desc lock is not enough to
     * protect us, and that we must ensure nobody samples vpe->col_idx
     * during the update, hence the lock below which must also be
     * taken on any vLPI handling path that evaluates vpe->col_idx.
     */
    from = vpe_to_cpuid_lock(vpe, &flags);
    if (from == cpu) {
        goto out;
    }

    vpe->col_idx = cpu;

    /*
     * GICv4.1 allows us to skip VMOVP if moving to a cpu whose RD
     * is sharing its VPE table with the current one.
     */
    if (gic_data_rdist_cpu(cpu)->vpe_table_mask && cpumask_test_cpu(from, gic_data_rdist_cpu(cpu)->vpe_table_mask)) {
        goto out;
    }

    its_send_vmovp(vpe);
    its_vpe_db_proxy_move(vpe, from, cpu);

out:
    irq_data_update_effective_affinity(d, cpumask_of(cpu));
    vpe_to_cpuid_unlock(vpe, flags);

    return IRQ_SET_MASK_OK_DONE;
}

static void its_wait_vpt_parse_complete(void)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val;

    if (!gic_rdists->has_vpend_valid_dirty) {
        return;
    }

    WARN_ON_ONCE(readq_relaxed_poll_timeout_atomic(vlpi_base + GICR_VPENDBASER, val, !(val & GICR_VPENDBASER_Dirty),
                                                   0xa, 0x1f4));
}

static void its_vpe_schedule(struct its_vpe *vpe)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val;

    /* Schedule the VPE */
    val = virt_to_phys(page_address(vpe->its_vm->vprop_page)) & GENMASK_ULL(0x33, 0xc);
    val |= (LPI_NRBITS - 1) & GICR_VPROPBASER_IDBITS_MASK;
    val |= GICR_VPROPBASER_RaWb;
    val |= GICR_VPROPBASER_InnerShareable;
    gicr_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);

    val = virt_to_phys(page_address(vpe->vpt_page)) & GENMASK_ULL(0x33, 0x10);
    val |= GICR_VPENDBASER_RaWaWb;
    val |= GICR_VPENDBASER_InnerShareable;
    /*
     * There is no good way of finding out if the pending table is
     * empty as we can race against the doorbell interrupt very
     * easily. So in the end, vpe->pending_last is only an
     * indication that the vcpu has something pending, not one
     * that the pending table is empty. A good implementation
     * would be able to read its coarse map pretty quickly anyway,
     * making this a tolerable issue.
     */
    val |= GICR_VPENDBASER_PendingLast;
    val |= vpe->idai ? GICR_VPENDBASER_IDAI : 0;
    val |= GICR_VPENDBASER_Valid;
    gicr_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
}

static void its_vpe_deschedule(struct its_vpe *vpe)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val;

    val = its_clear_vpend_valid(vlpi_base, 0, 0);

    vpe->idai = !!(val & GICR_VPENDBASER_IDAI);
    vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast);
}

static void its_vpe_invall(struct its_vpe *vpe)
{
    struct its_node *its;

    list_for_each_entry(its, &its_nodes, entry)
    {
        if (!is_v4(its)) {
            continue;
        }

        if (its_list_map && !vpe->its_vm->vlpi_count[its->list_nr]) {
            continue;
        }

        /*
         * Sending a VINVALL to a single ITS is enough, as all
         * we need is to reach the redistributors.
         */
        its_send_vinvall(its, vpe);
        return;
    }
}

static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_cmd_info *info = vcpu_info;

    switch (info->cmd_type) {
        case SCHEDULE_VPE:
            its_vpe_schedule(vpe);
            return 0;

        case DESCHEDULE_VPE:
            its_vpe_deschedule(vpe);
            return 0;

        case COMMIT_VPE:
            its_wait_vpt_parse_complete();
            return 0;

        case INVALL_VPE:
            its_vpe_invall(vpe);
            return 0;

        default:
            return -EINVAL;
    }
}

static void its_vpe_send_cmd(struct its_vpe *vpe, void (*cmd)(struct its_device *, u32))
{
    unsigned long flags;

    raw_spin_lock_irqsave(&vpe_proxy.lock, flags);

    its_vpe_db_proxy_map_locked(vpe);
    cmd(vpe_proxy.dev, vpe->vpe_proxy_event);

    raw_spin_unlock_irqrestore(&vpe_proxy.lock, flags);
}

static void its_vpe_send_inv(struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);

    if (gic_rdists->has_direct_lpi) {
        void __iomem *rdbase;

        /* Target the redistributor this VPE is currently known on */
        raw_spin_lock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
        rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
        gic_write_lpir(d->parent_data->hwirq, rdbase + GICR_INVLPIR);
        wait_for_syncr(rdbase);
        raw_spin_unlock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
    } else {
        its_vpe_send_cmd(vpe, its_send_inv);
    }
}

static void its_vpe_mask_irq(struct irq_data *d)
{
    /*
     * We need to unmask the LPI, which is described by the parent
     * irq_data. Instead of calling into the parent (which won't
     * exactly do the right thing, let's simply use the
     * parent_data pointer. Yes, I'm naughty.
     */
    lpi_write_config(d->parent_data, LPI_PROP_ENABLED, 0);
    its_vpe_send_inv(d);
}

static void its_vpe_unmask_irq(struct irq_data *d)
{
    /* Same hack as above... */
    lpi_write_config(d->parent_data, 0, LPI_PROP_ENABLED);
    its_vpe_send_inv(d);
}

static int its_vpe_set_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool state)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);

    if (which != IRQCHIP_STATE_PENDING) {
        return -EINVAL;
    }

    if (gic_rdists->has_direct_lpi) {
        void __iomem *rdbase;

        rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
        if (state) {
            gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_SETLPIR);
        } else {
            gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_CLRLPIR);
            wait_for_syncr(rdbase);
        }
    } else {
        if (state) {
            its_vpe_send_cmd(vpe, its_send_int);
        } else {
            its_vpe_send_cmd(vpe, its_send_clear);
        }
    }

    return 0;
}

static int its_vpe_retrigger(struct irq_data *d)
{
    return !its_vpe_set_irqchip_state(d, IRQCHIP_STATE_PENDING, true);
}

static struct irq_chip its_vpe_irq_chip = {
    .name = "GICv4-vpe",
    .irq_mask = its_vpe_mask_irq,
    .irq_unmask = its_vpe_unmask_irq,
    .irq_eoi = irq_chip_eoi_parent,
    .irq_set_affinity = its_vpe_set_affinity,
    .irq_retrigger = its_vpe_retrigger,
    .irq_set_irqchip_state = its_vpe_set_irqchip_state,
    .irq_set_vcpu_affinity = its_vpe_set_vcpu_affinity,
};

static struct its_node *find_4_1_its(void)
{
    static struct its_node *its = NULL;

    if (!its) {
        list_for_each_entry(its, &its_nodes, entry)
        {
            if (is_v4_1(its)) {
                return its;
            }
        }

        /* Oops? */
        its = NULL;
    }

    return its;
}

static void its_vpe_4_1_send_inv(struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_node *its;

    /*
     * GICv4.1 wants doorbells to be invalidated using the
     * INVDB command in order to be broadcast to all RDs. Send
     * it to the first valid ITS, and let the HW do its magic.
     */
    its = find_4_1_its();
    if (its) {
        its_send_invdb(its, vpe);
    }
}

static void its_vpe_4_1_mask_irq(struct irq_data *d)
{
    lpi_write_config(d->parent_data, LPI_PROP_ENABLED, 0);
    its_vpe_4_1_send_inv(d);
}

static void its_vpe_4_1_unmask_irq(struct irq_data *d)
{
    lpi_write_config(d->parent_data, 0, LPI_PROP_ENABLED);
    its_vpe_4_1_send_inv(d);
}

static void its_vpe_4_1_schedule(struct its_vpe *vpe, struct its_cmd_info *info)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val = 0;

    /* Schedule the VPE */
    val |= GICR_VPENDBASER_Valid;
    val |= info->g0en ? GICR_VPENDBASER_4_1_VGRP0EN : 0;
    val |= info->g1en ? GICR_VPENDBASER_4_1_VGRP1EN : 0;
    val |= FIELD_PREP(GICR_VPENDBASER_4_1_VPEID, vpe->vpe_id);

    gicr_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
}

static void its_vpe_4_1_deschedule(struct its_vpe *vpe, struct its_cmd_info *info)
{
    void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
    u64 val;

    if (info->req_db) {
        unsigned long flags;

        /*
         * vPE is going to block: make the vPE non-resident with
         * PendingLast clear and DB set. The GIC guarantees that if
         * we read-back PendingLast clear, then a doorbell will be
         * delivered when an interrupt comes.
         *
         * Note the locking to deal with the concurrent update of
         * pending_last from the doorbell interrupt handler that can
         * run concurrently.
         */
        raw_spin_lock_irqsave(&vpe->vpe_lock, flags);
        val = its_clear_vpend_valid(vlpi_base, GICR_VPENDBASER_PendingLast, GICR_VPENDBASER_4_1_DB);
        vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast);
        raw_spin_unlock_irqrestore(&vpe->vpe_lock, flags);
    } else {
        /*
         * We're not blocking, so just make the vPE non-resident
         * with PendingLast set, indicating that we'll be back.
         */
        val = its_clear_vpend_valid(vlpi_base, 0, GICR_VPENDBASER_PendingLast);
        vpe->pending_last = true;
    }
}

static void its_vpe_4_1_invall(struct its_vpe *vpe)
{
    void __iomem *rdbase;
    unsigned long flags;
    u64 val;
    int cpu;

    val = GICR_INVALLR_V;
    val |= FIELD_PREP(GICR_INVALLR_VPEID, vpe->vpe_id);

    /* Target the redistributor this vPE is currently known on */
    cpu = vpe_to_cpuid_lock(vpe, &flags);
    raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
    rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
    gic_write_lpir(val, rdbase + GICR_INVALLR);

    wait_for_syncr(rdbase);
    raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
    vpe_to_cpuid_unlock(vpe, flags);
}

static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_cmd_info *info = vcpu_info;

    switch (info->cmd_type) {
        case SCHEDULE_VPE:
            its_vpe_4_1_schedule(vpe, info);
            return 0;

        case DESCHEDULE_VPE:
            its_vpe_4_1_deschedule(vpe, info);
            return 0;

        case COMMIT_VPE:
            its_wait_vpt_parse_complete();
            return 0;

        case INVALL_VPE:
            its_vpe_4_1_invall(vpe);
            return 0;

        default:
            return -EINVAL;
    }
}

static struct irq_chip its_vpe_4_1_irq_chip = {
    .name = "GICv4.1-vpe",
    .irq_mask = its_vpe_4_1_mask_irq,
    .irq_unmask = its_vpe_4_1_unmask_irq,
    .irq_eoi = irq_chip_eoi_parent,
    .irq_set_affinity = its_vpe_set_affinity,
    .irq_set_vcpu_affinity = its_vpe_4_1_set_vcpu_affinity,
};

static void its_configure_sgi(struct irq_data *d, bool clear)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_cmd_desc desc;

    desc.its_vsgi_cmd.vpe = vpe;
    desc.its_vsgi_cmd.sgi = d->hwirq;
    desc.its_vsgi_cmd.priority = vpe->sgi_config[d->hwirq].priority;
    desc.its_vsgi_cmd.enable = vpe->sgi_config[d->hwirq].enabled;
    desc.its_vsgi_cmd.group = vpe->sgi_config[d->hwirq].group;
    desc.its_vsgi_cmd.clear = clear;

    /*
     * GICv4.1 allows us to send VSGI commands to any ITS as long as the
     * destination VPE is mapped there. Since we map them eagerly at
     * activation time, we're pretty sure the first GICv4.1 ITS will do.
     */
    its_send_single_vcommand(find_4_1_its(), its_build_vsgi_cmd, &desc);
}

static void its_sgi_mask_irq(struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);

    vpe->sgi_config[d->hwirq].enabled = false;
    its_configure_sgi(d, false);
}

static void its_sgi_unmask_irq(struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);

    vpe->sgi_config[d->hwirq].enabled = true;
    its_configure_sgi(d, false);
}

static int its_sgi_set_affinity(struct irq_data *d, const struct cpumask *mask_val, bool force)
{
    /*
     * There is no notion of affinity for virtual SGIs, at least
     * not on the host (since they can only be targetting a vPE).
     * Tell the kernel we've done whatever it asked for.
     */
    irq_data_update_effective_affinity(d, mask_val);
    return IRQ_SET_MASK_OK;
}

static int its_sgi_set_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool state)
{
    if (which != IRQCHIP_STATE_PENDING) {
        return -EINVAL;
    }

    if (state) {
        struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
        struct its_node *its = find_4_1_its();
        u64 val;

        val = FIELD_PREP(GITS_SGIR_VPEID, vpe->vpe_id);
        val |= FIELD_PREP(GITS_SGIR_VINTID, d->hwirq);
        writeq_relaxed(val, its->sgir_base + GITS_SGIR - SZ_128K);
    } else {
        its_configure_sgi(d, true);
    }

    return 0;
}

static int its_sgi_get_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool *val)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    void __iomem *base;
    unsigned long flags;
    u32 count = 0xf4240; /* 1s! */
    u32 status;
    int cpu;

    if (which != IRQCHIP_STATE_PENDING) {
        return -EINVAL;
    }

    /*
     * Locking galore! We can race against two different events:
     *
     * - Concurent vPE affinity change: we must make sure it cannot
     *   happen, or we'll talk to the wrong redistributor. This is
     *   identical to what happens with vLPIs.
     *
     * - Concurrent VSGIPENDR access: As it involves accessing two
     *   MMIO registers, this must be made atomic one way or another.
     */
    cpu = vpe_to_cpuid_lock(vpe, &flags);
    raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
    base = gic_data_rdist_cpu(cpu)->rd_base + SZ_128K;
    writel_relaxed(vpe->vpe_id, base + GICR_VSGIR);
    do {
        status = readl_relaxed(base + GICR_VSGIPENDR);
        if (!(status & GICR_VSGIPENDR_BUSY)) {
            goto out;
        }

        count--;
        if (!count) {
            pr_err_ratelimited("Unable to get SGI status\n");
            goto out;
        }
        cpu_relax();
        udelay(1);
    } while (count);

out:
    raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
    vpe_to_cpuid_unlock(vpe, flags);

    if (!count) {
        return -ENXIO;
    }

    *val = !!(status & (1 << d->hwirq));

    return 0;
}

static int its_sgi_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_cmd_info *info = vcpu_info;

    switch (info->cmd_type) {
        case PROP_UPDATE_VSGI:
            vpe->sgi_config[d->hwirq].priority = info->priority;
            vpe->sgi_config[d->hwirq].group = info->group;
            its_configure_sgi(d, false);
            return 0;

        default:
            return -EINVAL;
    }
}

static struct irq_chip its_sgi_irq_chip = {
    .name = "GICv4.1-sgi",
    .irq_mask = its_sgi_mask_irq,
    .irq_unmask = its_sgi_unmask_irq,
    .irq_set_affinity = its_sgi_set_affinity,
    .irq_set_irqchip_state = its_sgi_set_irqchip_state,
    .irq_get_irqchip_state = its_sgi_get_irqchip_state,
    .irq_set_vcpu_affinity = its_sgi_set_vcpu_affinity,
};

static int its_sgi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args)
{
    struct its_vpe *vpe = args;
    int i;

    /* Yes, we do want 16 SGIs */
    WARN_ON(nr_irqs != 0x10);

    for (i = 0; i < 0x10; i++) {
        vpe->sgi_config[i].priority = 0;
        vpe->sgi_config[i].enabled = false;
        vpe->sgi_config[i].group = false;

        irq_domain_set_hwirq_and_chip(domain, virq + i, i, &its_sgi_irq_chip, vpe);
        irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
    }

    return 0;
}

static void its_sgi_irq_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs)
{
    /* Nothing to do */
}

static int its_sgi_irq_domain_activate(struct irq_domain *domain, struct irq_data *d, bool reserve)
{
    /* Write out the initial SGI configuration */
    its_configure_sgi(d, false);
    return 0;
}

static void its_sgi_irq_domain_deactivate(struct irq_domain *domain, struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);

    /*
     * The VSGI command is awkward:
     *
     * - To change the configuration, CLEAR must be set to false,
     *   leaving the pending bit unchanged.
     * - To clear the pending bit, CLEAR must be set to true, leaving
     *   the configuration unchanged.
     *
     * You just can't do both at once, hence the two commands below.
     */
    vpe->sgi_config[d->hwirq].enabled = false;
    its_configure_sgi(d, false);
    its_configure_sgi(d, true);
}

static const struct irq_domain_ops its_sgi_domain_ops = {
    .alloc = its_sgi_irq_domain_alloc,
    .free = its_sgi_irq_domain_free,
    .activate = its_sgi_irq_domain_activate,
    .deactivate = its_sgi_irq_domain_deactivate,
};

static int its_vpe_id_alloc(void)
{
    return ida_simple_get(&its_vpeid_ida, 0, ITS_MAX_VPEID, GFP_KERNEL);
}

static void its_vpe_id_free(u16 id)
{
    ida_simple_remove(&its_vpeid_ida, id);
}

static int its_vpe_init(struct its_vpe *vpe)
{
    struct page *vpt_page;
    int vpe_id;

    /* Allocate vpe_id */
    vpe_id = its_vpe_id_alloc();
    if (vpe_id < 0) {
        return vpe_id;
    }

    /* Allocate VPT */
    vpt_page = its_allocate_pending_table(GFP_KERNEL);
    if (!vpt_page) {
        its_vpe_id_free(vpe_id);
        return -ENOMEM;
    }

    if (!its_alloc_vpe_table(vpe_id)) {
        its_vpe_id_free(vpe_id);
        its_free_pending_table(vpt_page);
        return -ENOMEM;
    }

    raw_spin_lock_init(&vpe->vpe_lock);
    vpe->vpe_id = vpe_id;
    vpe->vpt_page = vpt_page;
    if (gic_rdists->has_rvpeid) {
        atomic_set(&vpe->vmapp_count, 0);
    } else {
        vpe->vpe_proxy_event = -1;
    }

    return 0;
}

static void its_vpe_teardown(struct its_vpe *vpe)
{
    its_vpe_db_proxy_unmap(vpe);
    its_vpe_id_free(vpe->vpe_id);
    its_free_pending_table(vpe->vpt_page);
}

static void its_vpe_irq_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs)
{
    struct its_vm *vm = domain->host_data;
    int i;

    irq_domain_free_irqs_parent(domain, virq, nr_irqs);

    for (i = 0; i < nr_irqs; i++) {
        struct irq_data *data = irq_domain_get_irq_data(domain, virq + i);
        struct its_vpe *vpe = irq_data_get_irq_chip_data(data);

        BUG_ON(vm != vpe->its_vm);

        clear_bit(data->hwirq, vm->db_bitmap);
        its_vpe_teardown(vpe);
        irq_domain_reset_irq_data(data);
    }

    if (bitmap_empty(vm->db_bitmap, vm->nr_db_lpis)) {
        its_lpi_free(vm->db_bitmap, vm->db_lpi_base, vm->nr_db_lpis);
        its_free_prop_table(vm->vprop_page);
    }
}

static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args)
{
    struct irq_chip *irqchip = &its_vpe_irq_chip;
    struct its_vm *vm = args;
    unsigned long *bitmap;
    struct page *vprop_page;
    int base, nr_ids, i, err = 0;

    BUG_ON(!vm);

    bitmap = its_lpi_alloc(roundup_pow_of_two(nr_irqs), &base, &nr_ids);
    if (!bitmap) {
        return -ENOMEM;
    }

    if (nr_ids < nr_irqs) {
        its_lpi_free(bitmap, base, nr_ids);
        return -ENOMEM;
    }

    vprop_page = its_allocate_prop_table(GFP_KERNEL);
    if (!vprop_page) {
        its_lpi_free(bitmap, base, nr_ids);
        return -ENOMEM;
    }

    vm->db_bitmap = bitmap;
    vm->db_lpi_base = base;
    vm->nr_db_lpis = nr_ids;
    vm->vprop_page = vprop_page;

    if (gic_rdists->has_rvpeid) {
        irqchip = &its_vpe_4_1_irq_chip;
    }

    for (i = 0; i < nr_irqs; i++) {
        vm->vpes[i]->vpe_db_lpi = base + i;
        err = its_vpe_init(vm->vpes[i]);
        if (err) {
            break;
        }
        err = its_irq_gic_domain_alloc(domain, virq + i, vm->vpes[i]->vpe_db_lpi);
        if (err) {
            break;
        }
        irq_domain_set_hwirq_and_chip(domain, virq + i, i, irqchip, vm->vpes[i]);
        set_bit(i, bitmap);
    }

    if (err) {
        if (i > 0) {
            its_vpe_irq_domain_free(domain, virq, i);
        }

        its_lpi_free(bitmap, base, nr_ids);
        its_free_prop_table(vprop_page);
    }

    return err;
}

static int its_vpe_irq_domain_activate(struct irq_domain *domain, struct irq_data *d, bool reserve)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_node *its;

    /*
     * If we use the list map, we issue VMAPP on demand... Unless
     * we're on a GICv4.1 and we eagerly map the VPE on all ITSs
     * so that VSGIs can work.
     */
    if (!gic_requires_eager_mapping()) {
        return 0;
    }

    /* Map the VPE to the first possible CPU */
    vpe->col_idx = cpumask_first(cpu_online_mask);

    list_for_each_entry(its, &its_nodes, entry)
    {
        if (!is_v4(its)) {
            continue;
        }

        its_send_vmapp(its, vpe, true);
        its_send_vinvall(its, vpe);
    }

    irq_data_update_effective_affinity(d, cpumask_of(vpe->col_idx));

    return 0;
}

static void its_vpe_irq_domain_deactivate(struct irq_domain *domain, struct irq_data *d)
{
    struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
    struct its_node *its;

    /*
     * If we use the list map on GICv4.0, we unmap the VPE once no
     * VLPIs are associated with the VM.
     */
    if (!gic_requires_eager_mapping()) {
        return;
    }

    list_for_each_entry(its, &its_nodes, entry)
    {
        if (!is_v4(its)) {
            continue;
        }

        its_send_vmapp(its, vpe, false);
    }
}

static const struct irq_domain_ops its_vpe_domain_ops = {
    .alloc = its_vpe_irq_domain_alloc,
    .free = its_vpe_irq_domain_free,
    .activate = its_vpe_irq_domain_activate,
    .deactivate = its_vpe_irq_domain_deactivate,
};

static int its_force_quiescent(void __iomem *base)
{
    u32 count = 0xf4240; /* 1s */
    u32 val;

    val = readl_relaxed(base + GITS_CTLR);
    /*
     * GIC architecture specification requires the ITS to be both
     * disabled and quiescent for writes to GITS_BASER<n> or
     * GITS_CBASER to not have UNPREDICTABLE results.
     */
    if ((val & GITS_CTLR_QUIESCENT) && !(val & GITS_CTLR_ENABLE)) {
        return 0;
    }

    /* Disable the generation of all interrupts to this ITS */
    val &= ~(GITS_CTLR_ENABLE | GITS_CTLR_ImDe);
    writel_relaxed(val, base + GITS_CTLR);

    /* Poll GITS_CTLR and wait until ITS becomes quiescent */
    while (1) {
        val = readl_relaxed(base + GITS_CTLR);
        if (val & GITS_CTLR_QUIESCENT) {
            return 0;
        }

        count--;
        if (!count) {
            return -EBUSY;
        }

        cpu_relax();
        udelay(1);
    }
}

static bool __maybe_unused its_enable_quirk_cavium_22375(void *data)
{
    struct its_node *its = data;

    /* erratum 22375: only alloc 8MB table size (20 bits) */
    its->typer &= ~GITS_TYPER_DEVBITS;
    its->typer |= FIELD_PREP(GITS_TYPER_DEVBITS, 0x14 - 1);
    its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_22375;

    return true;
}

static bool __maybe_unused its_enable_quirk_cavium_23144(void *data)
{
    struct its_node *its = data;

    its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_23144;

    return true;
}

static bool __maybe_unused its_enable_quirk_qdf2400_e0065(void *data)
{
    struct its_node *its = data;

    /* On QDF2400, the size of the ITE is 16Bytes */
    its->typer &= ~GITS_TYPER_ITT_ENTRY_SIZE;
    its->typer |= FIELD_PREP(GITS_TYPER_ITT_ENTRY_SIZE, 0x10 - 1);

    return true;
}

static u64 its_irq_get_msi_base_pre_its(struct its_device *its_dev)
{
    struct its_node *its = its_dev->its;

    /*
     * The Socionext Synquacer SoC has a so-called 'pre-ITS',
     * which maps 32-bit writes targeted at a separate window of
     * size '4 << device_id_bits' onto writes to GITS_TRANSLATER
     * with device ID taken from bits [device_id_bits + 1:2] of
     * the window offset.
     */
    return its->pre_its_base + (its_dev->device_id << 0x2);
}

static bool __maybe_unused its_enable_quirk_socionext_synquacer(void *data)
{
    struct its_node *its = data;
    u32 pre_its_window[0x2];
    u32 ids;

    if (!fwnode_property_read_u32_array(its->fwnode_handle, "socionext,synquacer-pre-its", pre_its_window,
                                        ARRAY_SIZE(pre_its_window))) {

        its->pre_its_base = pre_its_window[0];
        its->get_msi_base = its_irq_get_msi_base_pre_its;

        ids = ilog2(pre_its_window[1]) - 0x2;
        if (device_ids(its) > ids) {
            its->typer &= ~GITS_TYPER_DEVBITS;
            its->typer |= FIELD_PREP(GITS_TYPER_DEVBITS, ids - 1);
        }

        /* the pre-ITS breaks isolation, so disable MSI remapping */
        its->msi_domain_flags &= ~IRQ_DOMAIN_FLAG_MSI_REMAP;
        return true;
    }
    return false;
}

static bool __maybe_unused its_enable_quirk_hip07_161600802(void *data)
{
    struct its_node *its = data;

    /*
     * Hip07 insists on using the wrong address for the VLPI
     * page. Trick it into doing the right thing...
     */
    its->vlpi_redist_offset = SZ_128K;
    return true;
}

static const struct gic_quirk its_quirks[] = {
#ifdef CONFIG_CAVIUM_ERRATUM_22375
    {
        .desc = "ITS: Cavium errata 22375, 24313",
        .iidr = 0xa100034c, /* ThunderX pass 1.x */
        .mask = 0xffff0fff,
        .init = its_enable_quirk_cavium_22375,
    },
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_23144
    {
        .desc = "ITS: Cavium erratum 23144",
        .iidr = 0xa100034c, /* ThunderX pass 1.x */
        .mask = 0xffff0fff,
        .init = its_enable_quirk_cavium_23144,
    },
#endif
#ifdef CONFIG_QCOM_QDF2400_ERRATUM_0065
    {
        .desc = "ITS: QDF2400 erratum 0065",
        .iidr = 0x00001070, /* QDF2400 ITS rev 1.x */
        .mask = 0xffffffff,
        .init = its_enable_quirk_qdf2400_e0065,
    },
#endif
#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS
    {
        /*
         * The Socionext Synquacer SoC incorporates ARM's own GIC-500
         * implementation, but with a 'pre-ITS' added that requires
         * special handling in software.
         */
        .desc = "ITS: Socionext Synquacer pre-ITS",
        .iidr = 0x0001143b,
        .mask = 0xffffffff,
        .init = its_enable_quirk_socionext_synquacer,
    },
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161600802
    {
        .desc = "ITS: Hip07 erratum 161600802",
        .iidr = 0x00000004,
        .mask = 0xffffffff,
        .init = its_enable_quirk_hip07_161600802,
    },
#endif
    {}};

static void its_enable_quirks(struct its_node *its)
{
    u32 iidr = readl_relaxed(its->base + GITS_IIDR);

    gic_enable_quirks(iidr, its_quirks, its);
}

static int its_save_disable(void)
{
    struct its_node *its;
    int err = 0;

    raw_spin_lock(&its_lock);
    list_for_each_entry(its, &its_nodes, entry)
    {
        void __iomem *base;

        base = its->base;
        its->ctlr_save = readl_relaxed(base + GITS_CTLR);
        err = its_force_quiescent(base);
        if (err) {
            pr_err("ITS@%pa: failed to quiesce: %d\n", &its->phys_base, err);
            writel_relaxed(its->ctlr_save, base + GITS_CTLR);
            goto err;
        }

        its->cbaser_save = gits_read_cbaser(base + GITS_CBASER);
    }

err:
    if (err) {
        list_for_each_entry_continue_reverse(its, &its_nodes, entry)
        {
            void __iomem *base;

            base = its->base;
            writel_relaxed(its->ctlr_save, base + GITS_CTLR);
        }
    }
    raw_spin_unlock(&its_lock);

    return err;
}

static void its_restore_enable(void)
{
    struct its_node *its;
    int ret;

    raw_spin_lock(&its_lock);
    list_for_each_entry(its, &its_nodes, entry)
    {
        void __iomem *base;
        int i;

        base = its->base;

        /*
         * Make sure that the ITS is disabled. If it fails to quiesce,
         * don't restore it since writing to CBASER or BASER<n>
         * registers is undefined according to the GIC v3 ITS
         * Specification.
         *
         * Firmware resuming with the ITS enabled is terminally broken.
         */
        WARN_ON(readl_relaxed(base + GITS_CTLR) & GITS_CTLR_ENABLE);
        ret = its_force_quiescent(base);
        if (ret) {
            pr_err("ITS@%pa: failed to quiesce on resume: %d\n", &its->phys_base, ret);
            continue;
        }

        gits_write_cbaser(its->cbaser_save, base + GITS_CBASER);

        /*
         * Writing CBASER resets CREADR to 0, so make CWRITER and
         * cmd_write line up with it.
         */
        its->cmd_write = its->cmd_base;
        gits_write_cwriter(0, base + GITS_CWRITER);

        /* Restore GITS_BASER from the value cache. */
        for (i = 0; i < GITS_BASER_NR_REGS; i++) {
            struct its_baser *baser = &its->tables[i];

            if (!(baser->val & GITS_BASER_VALID)) {
                continue;
            }

            its_write_baser(its, baser, baser->val);
        }
        writel_relaxed(its->ctlr_save, base + GITS_CTLR);

        /*
         * Reinit the collection if it's stored in the ITS. This is
         * indicated by the col_id being less than the HCC field.
         * CID < HCC as specified in the GIC v3 Documentation.
         */
        if (its->collections[smp_processor_id()].col_id < GITS_TYPER_HCC(gic_read_typer(base + GITS_TYPER))) {
            its_cpu_init_collection(its);
        }
    }
    raw_spin_unlock(&its_lock);
}

static struct syscore_ops its_syscore_ops = {
    .suspend = its_save_disable,
    .resume = its_restore_enable,
};

static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
{
    struct irq_domain *inner_domain;
    struct msi_domain_info *info;

    info = kzalloc(sizeof(*info), GFP_KERNEL);
    if (!info) {
        return -ENOMEM;
    }

    inner_domain = irq_domain_create_tree(handle, &its_domain_ops, its);
    if (!inner_domain) {
        kfree(info);
        return -ENOMEM;
    }

    inner_domain->parent = its_parent;
    irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
    inner_domain->flags |= its->msi_domain_flags;
    info->ops = &its_msi_domain_ops;
    info->data = its;
    inner_domain->host_data = info;

    return 0;
}

static int its_init_vpe_domain(void)
{
    struct its_node *its;
    u32 devid;
    int entries;

    if (gic_rdists->has_direct_lpi) {
        pr_info("ITS: Using DirectLPI for VPE invalidation\n");
        return 0;
    }

    /* Any ITS will do, even if not v4 */
    its = list_first_entry(&its_nodes, struct its_node, entry);

    entries = roundup_pow_of_two(nr_cpu_ids);
    vpe_proxy.vpes = kcalloc(entries, sizeof(*vpe_proxy.vpes), GFP_KERNEL);
    if (!vpe_proxy.vpes) {
        pr_err("ITS: Can't allocate GICv4 proxy device array\n");
        return -ENOMEM;
    }

    /* Use the last possible DevID */
    devid = GENMASK(device_ids(its) - 1, 0);
    vpe_proxy.dev = its_create_device(its, devid, entries, false);
    if (!vpe_proxy.dev) {
        kfree(vpe_proxy.vpes);
        pr_err("ITS: Can't allocate GICv4 proxy device\n");
        return -ENOMEM;
    }

    BUG_ON(entries > vpe_proxy.dev->nr_ites);

    raw_spin_lock_init(&vpe_proxy.lock);
    vpe_proxy.next_victim = 0;
    pr_info("ITS: Allocated DevID %x as GICv4 proxy device (%d slots)\n", devid, vpe_proxy.dev->nr_ites);

    return 0;
}

static int __init its_compute_its_list_map(struct resource *res, void __iomem *its_base)
{
    int its_number;
    u32 ctlr;

    /*
     * This is assumed to be done early enough that we're
     * guaranteed to be single-threaded, hence no
     * locking. Should this change, we should address
     * this.
     */
    its_number = find_first_zero_bit(&its_list_map, GICv4_ITS_LIST_MAX);
    if (its_number >= GICv4_ITS_LIST_MAX) {
        pr_err("ITS@%pa: No ITSList entry available!\n", &res->start);
        return -EINVAL;
    }

    ctlr = readl_relaxed(its_base + GITS_CTLR);
    ctlr &= ~GITS_CTLR_ITS_NUMBER;
    ctlr |= its_number << GITS_CTLR_ITS_NUMBER_SHIFT;
    writel_relaxed(ctlr, its_base + GITS_CTLR);
    ctlr = readl_relaxed(its_base + GITS_CTLR);
    if ((ctlr & GITS_CTLR_ITS_NUMBER) != (its_number << GITS_CTLR_ITS_NUMBER_SHIFT)) {
        its_number = ctlr & GITS_CTLR_ITS_NUMBER;
        its_number >>= GITS_CTLR_ITS_NUMBER_SHIFT;
    }

    if (test_and_set_bit(its_number, &its_list_map)) {
        pr_err("ITS@%pa: Duplicate ITSList entry %d\n", &res->start, its_number);
        return -EINVAL;
    }

    return its_number;
}

static int __init its_probe_one(struct resource *res, struct fwnode_handle *handle, int numa_node)
{
    struct its_node *its;
    void __iomem *its_base;
    u32 val, ctlr;
    u64 baser, tmp, typer;
    struct page *page;
    int err;
    gfp_t gfp_flags;

    its_base = ioremap(res->start, SZ_64K);
    if (!its_base) {
        pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
        return -ENOMEM;
    }

    val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK;
    if (val != 0x30 && val != 0x40) {
        pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start);
        err = -ENODEV;
        goto out_unmap;
    }

    err = its_force_quiescent(its_base);
    if (err) {
        pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start);
        goto out_unmap;
    }

    pr_info("ITS %pR\n", res);

    its = kzalloc(sizeof(*its), GFP_KERNEL);
    if (!its) {
        err = -ENOMEM;
        goto out_unmap;
    }

    raw_spin_lock_init(&its->lock);
    mutex_init(&its->dev_alloc_lock);
    INIT_LIST_HEAD(&its->entry);
    INIT_LIST_HEAD(&its->its_device_list);
    typer = gic_read_typer(its_base + GITS_TYPER);
    its->typer = typer;
    its->base = its_base;
    its->phys_base = res->start;
    if (is_v4(its)) {
        if (!(typer & GITS_TYPER_VMOVP)) {
            err = its_compute_its_list_map(res, its_base);
            if (err < 0) {
                goto out_free_its;
            }

            its->list_nr = err;

            pr_info("ITS@%pa: Using ITS number %d\n", &res->start, err);
        } else {
            pr_info("ITS@%pa: Single VMOVP capable\n", &res->start);
        }

        if (is_v4_1(its)) {
            u32 svpet = FIELD_GET(GITS_TYPER_SVPET, typer);

            its->sgir_base = ioremap(res->start + SZ_128K, SZ_64K);
            if (!its->sgir_base) {
                err = -ENOMEM;
                goto out_free_its;
            }

            its->mpidr = readl_relaxed(its_base + GITS_MPIDR);

            pr_info("ITS@%pa: Using GICv4.1 mode %08x %08x\n", &res->start, its->mpidr, svpet);
        }
    }

    its->numa_node = numa_node;

    gfp_flags = GFP_KERNEL | __GFP_ZERO;
    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        gfp_flags |= GFP_DMA32;
    }
    page = alloc_pages_node(its->numa_node, gfp_flags, get_order(ITS_CMD_QUEUE_SZ));
    if (!page) {
        err = -ENOMEM;
        goto out_unmap_sgir;
    }
    its->cmd_base = (void *)page_address(page);
    its->cmd_write = its->cmd_base;
    its->fwnode_handle = handle;
    its->get_msi_base = its_irq_get_msi_base;
    its->msi_domain_flags = IRQ_DOMAIN_FLAG_MSI_REMAP;

    its_enable_quirks(its);

    err = its_alloc_tables(its);
    if (err) {
        goto out_free_cmd;
    }

    err = its_alloc_collections(its);
    if (err) {
        goto out_free_tables;
    }

    baser = (virt_to_phys(its->cmd_base) | GITS_CBASER_RaWaWb | GITS_CBASER_InnerShareable |
             (ITS_CMD_QUEUE_SZ / SZ_4K - 1) | GITS_CBASER_VALID);

    gits_write_cbaser(baser, its->base + GITS_CBASER);
    tmp = gits_read_cbaser(its->base + GITS_CBASER);

    if (of_machine_is_compatible("rockchip,rk3568") || of_machine_is_compatible("rockchip,rk3566")) {
        tmp &= ~GITS_CBASER_SHAREABILITY_MASK;
    }

    if ((tmp ^ baser) & GITS_CBASER_SHAREABILITY_MASK) {
        if (!(tmp & GITS_CBASER_SHAREABILITY_MASK)) {
            /*
             * The HW reports non-shareable, we must
             * remove the cacheability attributes as
             * well.
             */
            baser &= ~(GITS_CBASER_SHAREABILITY_MASK | GITS_CBASER_CACHEABILITY_MASK);
            baser |= GITS_CBASER_nC;
            gits_write_cbaser(baser, its->base + GITS_CBASER);
        }
        pr_info("ITS: using cache flushing for cmd queue\n");
        its->flags |= ITS_FLAGS_CMDQ_NEEDS_FLUSHING;
    }

    gits_write_cwriter(0, its->base + GITS_CWRITER);
    ctlr = readl_relaxed(its->base + GITS_CTLR);
    ctlr |= GITS_CTLR_ENABLE;
    if (is_v4(its)) {
        ctlr |= GITS_CTLR_ImDe;
    }
    writel_relaxed(ctlr, its->base + GITS_CTLR);

    err = its_init_domain(handle, its);
    if (err) {
        goto out_free_tables;
    }

    raw_spin_lock(&its_lock);
    list_add(&its->entry, &its_nodes);
    raw_spin_unlock(&its_lock);

    return 0;

out_free_tables:
    its_free_tables(its);
out_free_cmd:
    free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
out_unmap_sgir:
    if (its->sgir_base) {
        iounmap(its->sgir_base);
    }
out_free_its:
    kfree(its);
out_unmap:
    iounmap(its_base);
    pr_err("ITS@%pa: failed probing (%d)\n", &res->start, err);
    return err;
}

static bool gic_rdists_supports_plpis(void)
{
    return !!(gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER) & GICR_TYPER_PLPIS);
}

static int redist_disable_lpis(void)
{
    void __iomem *rbase = gic_data_rdist_rd_base();
    u64 timeout = USEC_PER_SEC;
    u64 val;

    if (!gic_rdists_supports_plpis()) {
        pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
        return -ENXIO;
    }

    val = readl_relaxed(rbase + GICR_CTLR);
    if (!(val & GICR_CTLR_ENABLE_LPIS)) {
        return 0;
    }

    /*
     * If coming via a CPU hotplug event, we don't need to disable
     * LPIs before trying to re-enable them. They are already
     * configured and all is well in the world.
     *
     * If running with preallocated tables, there is nothing to do.
     */
    if (gic_data_rdist()->lpi_enabled || (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED)) {
        return 0;
    }

    /*
     * From that point on, we only try to do some damage control.
     */
    pr_warn("GICv3: CPU%d: Booted with LPIs enabled, memory probably corrupted\n", smp_processor_id());
    add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);

    /* Disable LPIs */
    val &= ~GICR_CTLR_ENABLE_LPIS;
    writel_relaxed(val, rbase + GICR_CTLR);

    /* Make sure any change to GICR_CTLR is observable by the GIC */
    dsb(sy);

    /*
     * Software must observe RWP==0 after clearing GICR_CTLR.EnableLPIs
     * from 1 to 0 before programming GICR_PEND{PROP}BASER registers.
     * Error out if we time out waiting for RWP to clear.
     */
    while (readl_relaxed(rbase + GICR_CTLR) & GICR_CTLR_RWP) {
        if (!timeout) {
            pr_err("CPU%d: Timeout while disabling LPIs\n", smp_processor_id());
            return -ETIMEDOUT;
        }
        udelay(1);
        timeout--;
    }

    /*
     * After it has been written to 1, it is IMPLEMENTATION
     * DEFINED whether GICR_CTLR.EnableLPI becomes RES1 or can be
     * cleared to 0. Error out if clearing the bit failed.
     */
    if (readl_relaxed(rbase + GICR_CTLR) & GICR_CTLR_ENABLE_LPIS) {
        pr_err("CPU%d: Failed to disable LPIs\n", smp_processor_id());
        return -EBUSY;
    }

    return 0;
}

int its_cpu_init(void)
{
    if (!list_empty(&its_nodes)) {
        int ret;

        ret = redist_disable_lpis();
        if (ret) {
            return ret;
        }

        its_cpu_init_lpis();
        its_cpu_init_collections();
    }

    return 0;
}

static const struct of_device_id its_device_id[] = {
    {
        .compatible = "arm,gic-v3-its",
    },
    {},
};

static int __init its_of_probe(struct device_node *node)
{
    struct device_node *np;
    struct resource res;

    for (np = of_find_matching_node(node, its_device_id); np; np = of_find_matching_node(np, its_device_id)) {
        if (!of_device_is_available(np)) {
            continue;
        }
        if (!of_property_read_bool(np, "msi-controller")) {
            pr_warn("%pOF: no msi-controller property, ITS ignored\n", np);
            continue;
        }

        if (of_address_to_resource(np, 0, &res)) {
            pr_warn("%pOF: no regs?\n", np);
            continue;
        }

        its_probe_one(&res, &np->fwnode, of_node_to_nid(np));
    }
    return 0;
}

#ifdef CONFIG_ACPI

#define ACPI_GICV3_ITS_MEM_SIZE (SZ_128K)

#ifdef CONFIG_ACPI_NUMA
struct its_srat_map {
    /* numa node id */
    u32 numa_node;
    /* GIC ITS ID */
    u32 its_id;
};

static struct its_srat_map *its_srat_maps __initdata;
static int its_in_srat __initdata;

static int __init acpi_get_its_numa_node(u32 its_id)
{
    int i;

    for (i = 0; i < its_in_srat; i++) {
        if (its_id == its_srat_maps[i].its_id) {
            return its_srat_maps[i].numa_node;
        }
    }
    return NUMA_NO_NODE;
}

static int __init gic_acpi_match_srat_its(union acpi_subtable_headers *header, const unsigned long end)
{
    return 0;
}

static int __init gic_acpi_parse_srat_its(union acpi_subtable_headers *header, const unsigned long end)
{
    int node;
    struct acpi_srat_gic_its_affinity *its_affinity;

    its_affinity = (struct acpi_srat_gic_its_affinity *)header;
    if (!its_affinity) {
        return -EINVAL;
    }

    if (its_affinity->header.length < sizeof(*its_affinity)) {
        pr_err("SRAT: Invalid header length %d in ITS affinity\n", its_affinity->header.length);
        return -EINVAL;
    }

    /*
     * Note that in theory a new proximity node could be created by this
     * entry as it is an SRAT resource allocation structure.
     * We do not currently support doing so.
     */
    node = pxm_to_node(its_affinity->proximity_domain);

    if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
        pr_err("SRAT: Invalid NUMA node %d in ITS affinity\n", node);
        return 0;
    }

    its_srat_maps[its_in_srat].numa_node = node;
    its_srat_maps[its_in_srat].its_id = its_affinity->its_id;
    its_in_srat++;
    pr_info("SRAT: PXM %d -> ITS %d -> Node %d\n", its_affinity->proximity_domain, its_affinity->its_id, node);

    return 0;
}

static void __init acpi_table_parse_srat_its(void)
{
    int count;

    count = acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat), ACPI_SRAT_TYPE_GIC_ITS_AFFINITY,
                                     gic_acpi_match_srat_its, 0);
    if (count <= 0) {
        return;
    }

    its_srat_maps = kmalloc_array(count, sizeof(struct its_srat_map), GFP_KERNEL);
    if (!its_srat_maps) {
        pr_warn("SRAT: Failed to allocate memory for its_srat_maps!\n");
        return;
    }

    acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat), ACPI_SRAT_TYPE_GIC_ITS_AFFINITY,
                             gic_acpi_parse_srat_its, 0);
}

/* free the its_srat_maps after ITS probing */
static void __init acpi_its_srat_maps_free(void)
{
    kfree(its_srat_maps);
}
#else
static void __init acpi_table_parse_srat_its(void)
{
}
static int __init acpi_get_its_numa_node(u32 its_id)
{
    return NUMA_NO_NODE;
}
static void __init acpi_its_srat_maps_free(void)
{
}
#endif

static int __init gic_acpi_parse_madt_its(union acpi_subtable_headers *header, const unsigned long end)
{
    struct acpi_madt_generic_translator *its_entry;
    struct fwnode_handle *dom_handle;
    struct resource res;
    int err;

    its_entry = (struct acpi_madt_generic_translator *)header;
    memset(&res, 0, sizeof(res));
    res.start = its_entry->base_address;
    res.end = its_entry->base_address + ACPI_GICV3_ITS_MEM_SIZE - 1;
    res.flags = IORESOURCE_MEM;

    dom_handle = irq_domain_alloc_fwnode(&res.start);
    if (!dom_handle) {
        pr_err("ITS@%pa: Unable to allocate GICv3 ITS domain token\n", &res.start);
        return -ENOMEM;
    }

    err = iort_register_domain_token(its_entry->translation_id, res.start, dom_handle);
    if (err) {
        pr_err("ITS@%pa: Unable to register GICv3 ITS domain token (ITS ID %d) to IORT\n", &res.start,
               its_entry->translation_id);
        goto dom_err;
    }

    err = its_probe_one(&res, dom_handle, acpi_get_its_numa_node(its_entry->translation_id));
    if (!err) {
        return 0;
    }

    iort_deregister_domain_token(its_entry->translation_id);
dom_err:
    irq_domain_free_fwnode(dom_handle);
    return err;
}

static void __init its_acpi_probe(void)
{
    acpi_table_parse_srat_its();
    acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, gic_acpi_parse_madt_its, 0);
    acpi_its_srat_maps_free();
}
#else
static void __init its_acpi_probe(void)
{
}
#endif

int __init its_init(struct fwnode_handle *handle, struct rdists *rdists, struct irq_domain *parent_domain)
{
    struct device_node *of_node;
    struct its_node *its;
    bool has_v4 = false;
    bool has_v4_1 = false;
    int err;

    gic_rdists = rdists;

    its_parent = parent_domain;
    of_node = to_of_node(handle);
    if (of_node) {
        its_of_probe(of_node);
    } else {
        its_acpi_probe();
    }

    if (list_empty(&its_nodes)) {
        pr_warn("ITS: No ITS available, not enabling LPIs\n");
        return -ENXIO;
    }

    err = allocate_lpi_tables();
    if (err) {
        return err;
    }

    list_for_each_entry(its, &its_nodes, entry)
    {
        has_v4 |= is_v4(its);
        has_v4_1 |= is_v4_1(its);
    }

    /* Don't bother with inconsistent systems */
    if (WARN_ON(!has_v4_1 && rdists->has_rvpeid)) {
        rdists->has_rvpeid = false;
    }

    if (has_v4 & rdists->has_vlpis) {
        const struct irq_domain_ops *sgi_ops;

        if (has_v4_1) {
            sgi_ops = &its_sgi_domain_ops;
        } else {
            sgi_ops = NULL;
        }

        if (its_init_vpe_domain() || its_init_v4(parent_domain, &its_vpe_domain_ops, sgi_ops)) {
            rdists->has_vlpis = false;
            pr_err("ITS: Disabling GICv4 support\n");
        }
    }

    register_syscore_ops(&its_syscore_ops);

    return 0;
}
